Cut the tubing where the storage area is. You can easily do this with it in place. Then use a drop of glue above and below to fix it to the tube so the top section doesn't slide down. Because the foam is so thick it likely won't make contact in the area where the foam is removed.

You are being too picky. Mondince is probably one of the better sellers to work with on the lower end of the price spectrum, but they're still 1/3 - 1/4 the price of the higher end Chinese frame companies such as XMCS, Lightcarbon, Winspace, Quickpro, etc. They do a good job in my experience - when I had an issue with the saddle clamp for the offset seat post that my FM336 came  with I reached out to Jack for replacement hardware since the issue was one of the cross/barrel nuts. Jack ended up sending me replacement hardware as well as an entire zero offset seat post for free that got to me within a week. Are the brake mounting posts perfectly flat and pristine on my frame and fork? No, but they were masked well during painting and flat enough to have minimal rub. I ordered a facing tool to improve them, but it's such a minor problem I haven't felt the urge to face them just yet.

The rivets are a miss, yes. I would've been interested in hearing how they address that but it sounds like you'd be better served by one of the bigger players. I think for those looking for quality frames in the $500-800 range that may require a small amount of finishing work Mondince is a better option than SPCycle, Meinier, Seraph, etc. Light Cycling seems promising, but no one has built one up yet so the verdict is still out for them.

The candy red looks fantastic in the light. Might have to do something similar with my next build.

Looks like it's taken a bit of a beating. No ideas from me, but IGPSPORT has been quick to get back to me on feedback and questions I've had, so hopefully they can help you out.

The dark green goes great with the tan wall tires.

Did Light Cycling say they will paint the frame storage cover? I'm curious because my Mondince FM336 came with it painted, but I've seen some reports that Mondince won't paint it for this frame due to warpage issues. Looking forward to seeing how your paint job comes out.

I tried looking up pricing on NOSIG the last time you mentioned it but cannot find anywhere selling the wheels. The NOSIG website lists an absurd price of $9999. They're interesting, but they seem impossible to buy.

Last year I communicated with Serenade over Whatsapp to have a set of MTB wheels with non-standard orange Koozer hubs built up, but those were with standard J bend spokes and I know carbon spokes can be somewhat nonstandard when it comes to hub compatibility. Let us know what they say.