if you happen to have a desktop PC and you play while at home, sometimes remote play on the deck is better than installing a game on the deck

I can remote play Elden Ring from my desktop at 60fps with longer battery life vs 40fps if installed on the deck with worse battery life

also make sure you try out reduced TDP and GPU rates on games with simpler graphics, you can get an extra 1-2 hours of battery life and not impact performance in certain cases