You can't trust him, but I don't think he has a play where backstabbing works out for him. Toppo wrecked Frieza's shit and Jiren is beyond god tier. Unless U11 gets knocked down to just 1 person left, there isn't much leverage Frieza would have and Jiren only joined because he wants the wish, so Frieza's "wish me back" request would be denied. At this point, his best chance of survival is making sure U7 has more people left on the stage when time runs out. Unless Zeno changes the rules and forces knock outs/enacts a sudden death mode. There are only about 9 episodes left before they take their hiatus and you figure at least 2-3 will be post tournament episodes.