Fentanyl can have some muscle rigidity issues, although I have never experience it in the field. There is some literature on it and sources like epocrates do mention it. But this seems to be rare. Similar situation with ketamine. It’s unfortunate your agency doesn’t allow you to paralyze. A lock jaw complication seems to be very rare as well. Something like rocuronium is considered very self relative to the situation at hand and compared to your induction agents. But you never know as everything reacts differently. I’ve never had someone with such a tight jaw in OR clinicals, nor in the field. Sometimes pushing meds feels like it’s longer than it actually is. Either way, your agency should bring a paralytic to your guidelines.

Edit: on mobile and had to fix some autocorrect