That's a good point. To me there is no downside. The season is a train wreck as it is. His presence does nothing to change the fact that they will finish-
at best- 5-12.
As others have said there IS some possible upside- either he does reasonably well the final 5 games (I just can't see him starting Thursday Night) and if he attracts other suitors the Rams net a 2024 comp pick. Or he does alright and they see enough in him to bring back as the QB2. Either would beneficial.
If he comes in plays terribly, well, whatever.....