i ran full treble process ...then ran treble GSI ..very good experience with ViperOs Pie GSI ...battery life was fine ...now I'm running another rom ..with same recovery ( treble) ...battery is good ..SOT maybe 4-6 hours depending on brightness setting etc ...standby 2 days ...moderate use and standby 1.5 days ..
if you have a problem it is
- your personal settings
-some rogue application
highly doubt it is related to this build or the treble recovery friend ...