I am finally done with it.
I did take my time and I did run into the same issue as you with the hidden nut haha. I ended up buying a pack of 25 drop in T-nuts after that just in case.
Aside of that I made a few mods to it already before being done building it. I didn't want to have to take it appart to do any mods afterward.
Here is the final result of the build.









I ended up buying some 12V COB LED daytime running lights I wired to the PSU alongside the fans($7). They are mounted on 3D printed adjustable brackets.
Cable management was done with some medium home audio/video concealing tracks (not the cheapest way to do it).
I used 7x7 cable tracks for the Z stepper and limit switch and some 10x15 for everything on the Hot End carrier(about $14/17).
I 3D printed a mount for the cable track to attach to the Hot End carrier like so:









I am very curious at how the self leveling kit works?
I used the leveling function from the firmware and it did not seem to do the trick on my first test print.
Lmk if you are interested in the cable track mounting piece, I will gladly share my STL for that.