From what I understand, Last Epoch has an online and offline mode. If you're playing in online mode, and you put your deck to sleep, what happens when you wake up the Deck?
Some online games just have a brief reconnecting delay, but other games (like Diablo 4 at launch) will completely kick you out or make you restart the game completely.
Some of the Yakuza games seem to benefit a lot from a TDP limit. Seems like you can restrict the power usage quite a bit without any decrease in performance.