[dsraven]

I also have a couple of long levels but my go to is still the digital torpedo level. lots of times that gets placed on the long level to check and/or recheck angles, especially after doing some work like removing or installing something heavy to the frame, an IFS cross member, control arm angles, etc. I don't have a frame stand but I do have some modified jack stands with some 3/4" threaded rod on the uprights. they work great to dial in a frame for level side to side or to get the rake angle needed. the top of the threaded rod has a smaller bolt welded on so it can pass through a hole in the frame and be locked down to keep things from moving.
your work looks awesome. nicely fabbed brackets and attention to detail. it all takes time to think it through with how this will affect that later on in the build.