Unobtanium

This is true. I've kindof got my "standard modifications" for M4's at this point, lol!

Big facts. I'm waiting on my 2nd Entry model, as well. No desire to own the others.

Several reasons... 1) the AR love was driven hard by GWOT. GWOT is winding down. 2) Market saturation. The AR market is saturated to the point of absurdity. Look at Aridus Ind and FFT. They have niched their way into mainstream by supporting solidly the shotgun market. I bet neither could have even touched the AR market with this level of success. 3) Democrats are in power and people want something 50 state legal or future proofed or maybe even their local laws have shafted them.

I file it under "more is better and why not?" A 100% increase in surface area isn't a bad thing in this case, IMO

I went with the FFT rail to provide more surface area for the crossbar of the mount. All mounts will shift/slide during recoil and bolt return, even on 5.56 guns. On a 12 gauge, this is absolutely brutal, so I want to provide the most surface area possible for the recoil lug/cross-bar to interface with.

You want the LPA BAR D4. It is currently out of stock where I normally source them: https://fusionfirearms.com/standard-ghost-ring-d4

No. I have never found this to be the case, and even on my pistols I have sometimes run "blackout" sights like the ones Kyle Defoor branded. Why? I am using a light. It is bright AF. My sights, even if they are neon green 532nm retina searing acid jello color, are going to be "black" when viewed in relief behind my WML. The other aspect is night sights that you brought up, not just bright colored sights. There is some utility to them in very low light if you are not using a WML, but this is going to probably fall under irresponsible use, as you are not likely to PID your target unless the target area is well lit...and then we again have the sights black in stark relief. Next is the ghost ring tritium close to your eye. This is terrible. It will mess with your natural night vision and cause pupillary constriction and it just sucks. The only people I know who DO run night sights on long guns forego the rears. Night sights under NODS are a detriment for obvious reasons. In short, I replace my rear ghost ring with a plain black one from LPA that does not have the dots/ "wings", and I remove the FSP, clean out the reactive paint, replace it with white automotive touch-up paint, clear-coat over it with automotive touch-up clear coat, and re-install it. It looks factory and gets rid of the stupid glowing FSP.

I moved to the FFT rail + ADM Ti mount and whatever optic is your flavor. For me, that's T-series micros. Why? I want the ability to use irons if my optic fails...that is a huge reason for "can I see irons through the optic?" However, optics do not often just take a dump where the lights go out. We have evolved to the point that optics are honestly pretty darn reliable in and of themselves. Even on a gauge. So what causes optics to fail? In my case, it has been rain. You get rain on lenses, it can freeze (I hunt in the midwest, and sometimes it rains, drizzles, then freezes as the day goes on, etc.) or you get intractable fogging no matter what you treated it with. This causes it to be a royal pain or even impossible to use the RDS. I use closed emitter types, but even worse with open emitters like RMR. This makes "seeing my irons through the window" an equally trash idea to implement. If the dot is messed up due to optical distortion, the FSP will likely not be super awesome to visualize, either. Maybe for you this is mud, snow, took a sim round to the window, whatever. But for me, it's humidity/rain and cold related. With a SYNC, you are then stuck. You will not be easily aiming that weapon. You have lost both primary and backup sighting methods because something got rained on and temps dropped, or mud, or whatever. With a QD system like the ADM Ti mount, I can pop the optic off, stow it in my pocket, and finish the hunt/training course/whatever. Further, the ADM Ti on a 1913 rail places the optic a hair higher than the SYNC, which is PERFECT for the mid setting of the C-Stock without NODS. With NODS, it places the optic higher for better use with NODS with the stock fully extended. It really is the "sweet spot", while the SYNC is more tuned toward being a good cheek weld without NODS, with the stock fully out. I prefer to run the stock on the mid (12.25" LOP) setting when I'm not running NODS. Further still is attachment method. I prefer 5 screws to 2, with 2 locators. So far, the ADM Ti mount has held up EXCELLENT and I have had no issues of any kind with it regarding zero shift or any other malady. The new Ti levers/bolts are physically much stronger than the previous iterations.

I have never had this issue, but it has been a very very near thing, to the point that I wondered about it. As much as I love the SYNC, I have transitioned away from it to other solutions.

Un screw the tail cap end. They make a special tool for it, or you can take needle nose or similar pliars, place them in the indents, and unscrew it. This will allow removal of the clip as well as replacement of the boot if necessary at any juncture.

Buy one from Carrier Comp. Recoil too much. Inertia. This was your issue.

No issues with it. That said, Remington just got back to running, maybe the new stuff had a qc issue?

I used CC exclusively in the past. Ive known Kip for nearly a decade and his products are beyond top notch.

I only use factory SBS M4s. I just leave the oem in place.

From memory in the past, when I tighten the mag cap on a Ti mag tube, its kindof like a jar lid. You can get it reeeeeaalllly tight. Squeeze in another click or two. On the steel tubes, it just dead stops. Ive also noticed on Ti tube guns with an optic, at 25m, I can observe slugs walking vertically as the barrel heats. Not on steel tube guns. Using just iron sights, this is hidden, as the FSP moves, too. Need to test this with receiver only mounted sighting system. YMMV, and my sample size is not large enough to leave the realm of anecdotal

Steel will flex less, but Ti is far lighter. You get to decide which is right for your needs.

Weight vs. Performance. Could I run an Arisaka M300 body and hyperthrow M300 head and shave 2oz off the front? I sure could. I'd lose my IR capability, though. Could I run an M300V instead of an M600V? Yup. Then I'd get more shadow on the barrel and FS, which is annoying especially under NODS. Could I run a Ti or CF mag tube? Yup. It would shave some ounces, but it would flex more under firing and accuracy and durability would technically be affected. Could I run a polymer trigger guard and save an oz over the milspec ones I prefer? Yes, but I prefer aluminum as that is what Aberdeen vetted the gun with. That said, I cannot tell you the polymer is worse and support my statement. Could I run a RMR or Holosun and not an Aimpoint Micro? I could, but then my light transmission under NODS would suffer. I've looked at all the things, and thus far, my weapon is as light as can be without making compromises I do not wish to make.

I use Peltor Tac6s on my helmet. Otherwise just regular 3M foam orange. Roll them between finger and thumb. Then reach behind your head, left arm right ear, pick up the top of the ear and pull like youre trying to drag the ear over and around your head to your other ear. Insert plug. Let it expand. Technique matters!

Raise your optic and adopt a more upright head position. While not the answer you want, it is the inky ergonomically sound option, given your dislike of in-ear options.

Ultimately, I just went to an m600v and T2. Lasers just don't have a good attachment place at this time as best I can tell, aside the top rail. Maybe an EOLAD or similar, but that's chonky.

It is not.

Yes

Change to a Tactician style cap. https://www.lumensfactory.com/en/product_detail.php?pid=501

Normal. No issue.