Thompson was not consistent so far in the Finals, however, he is still very dangerous, when he is hot, he can shoot with a good 3 point percentage so I would still continue trusting him. Remember in the last few series, he have some big games, game 5 vs Dallas and game 6 vs Memphis. He was the closer.
If Thompson is playing bad there is Pool to cover the deficiency or to lessen the burden, I dont know why people are still thinking about Klay when Pool has also a good impact on the team.