I *think* this is what I was practically screaming at the book for Jasnah to do, and afterwards I completely stopped caring about her character in any meaningful way. This should have been a lay-up of an argument to win, and she already said the thing that should have won it. Todium had already betrayed them once, and with so much more knowledge and resources now it's practically a guarantee that he will betray them again, and much more thoroughly, later. Jasnah could say, rightfully, that there is no way for a limited human to make a contract with a god that the god could not build in a thousand ways to subvert given enough resources and time, which Todium clearly has, by his own admission. Yes, Jasnah might betray them for what is perceived as the greater good for her people, but Todium almost certainly will, and the betrayal would be much more severe given Todium's immense power and capacity for cruelty. Yes, Todium is bound more strongly by pacts but, as they already stated in the conversation, he can find very inventive was of bending a pact to his advantage without technically violating it.
In the end I got the impression that Jasnah was simply not very good and what we've been told she's good at, and that made her a rather worthless character for me. She wasn't trapped in an unwinnable confrontation, she went in wildly unprepared for what Todium would say (somehow not even considering that Todium would attack her credibility, are you kidding me??) and she didn't argue her strongest point enough about how untrustworthy Todium was. Disappointing and character-destroying, which might have been the point but we've spent so much time building her up that it feels wrong, like when I re-read the books I'll just roll my eyes and skip her chapters because all of it comes to nothing in the end.
Loved the other character arcs :).