Didn't see this posted on this board, but the Evo 4G has the same 4G setup as the Evo Shift, so you can make the same changes. It should allow your to connect to lower Db 4G networks, and drop the connection less often. You just need your MSL, which you can get from Sprint, or use MSL Reader in the market.
[GUIDE - YMMV] Connect to 4G sooner & stay on longer - xda-developers