[Hectic]

For the money that a pair of bridge tensioners cost vs the time assembling and reassembling to test fit what I refer to as a "welfare nub" that may never work as well as a nub manufactured with good tolerances isn't worth it to me. The modify nub isn't all that great in an m4 type hop up (the nub doesn't fill the whole hop window) but the promy flat or bridge is great.
If you have the time, tools, skills and a steady hand it may be worth your effort to make one, but my time is worth at least 150 bucks an hour to me so spending 20 bucks on a pair of nubs pays for itself on 1 install.