I’ve been using MusicLab Real Guitars for quite a while now. I noticed also that they hit 100% instantly and stay there. However, nothing seems to go wrong and the guitars perform well. I did ask on this forum about a year ago about this very same problem, but I just forget about it and carry on.
Real Guitars were causing GP to crash for me in a major way for a while, and on the recommendations from the developers of GP, I contacted MusicLab. They discovered some (in their words) very nasty bugs. I became a tester for a series of upgrades and after three or four revisions, they issued me with updated versions that have been very stable since. If you experience crashing of GP, check the crash logs and see if RG is the culprit. BTW - I have every single RG and use them all live with a Guitar Hero wireless controller. The GH controller is my main midi controller along with an iPad running OnSong.