Actually, dramatic-irony-wise, wouldn't signing a happy and beautifully symbolic contract like this make it a great time for something terrible to happen to Carissa just before her actual afterlife arrangements got made? There's hardly any author in dath ilan who would, if planning to have Carissa kidnapped in the next few hours, not have this beautiful emotional additional option contract get signed first. Only a Genre Savvy character's explicit awareness of the trope could possibly prevent that, because the author really can't do that so freely if the protagonist is smart enough to notice, and even then the protagonist would need to -
"On due reflection, I think the level of 'trope' alarm this entire situation is generating is sufficient that I literally don't want to let you out of my sight until the devil gets back," Keltham states. "I may entertain arguments that you be allowed to use the bathroom."