I would think having the proper lines of the original 180 lower was kind of the whole point of having a retro 180 build
I was trying to wring out my 10.5" 5.56 gen 2 upper enough to kind of validate it before I marked the lower as an SBR (the 10.5 just isn't reliable enough to do that, so far, even after the PWS piston upgrade)...now I'm glad I didn't mark the lower if they're being discontinued.
Especially now that NoDak Spud isn't a thing anymore and they're not cranking out any almost-clone-perfect lowers anymore..