I removed my U.N.-leveling feet for the same reason and have no regrets. Like Mike said you will likely have to level the surface underneath the machine afterwards, but it will definitely help with the center sag issue. Here’s a forum post with my leveling journey if you have some time to kill reading:
As a side note: A couple nights ago I cleared the bed of my machine for the first time since I initially cleared it back when I made that forum post. I took off 0.010” on my first pass and it cleared all but a maybe 2”x4” spot on my waste board setup(I made pencil marks all over so I could easily see any missed spots). Second pass at 0.010” came out perfectly clean. I’d say it’s pretty flat and stable, definitely better than with the feet. Really happy with the results.
Dan