Have you considered using woody bands or bands to assist you with your pullup progression?
Honestly, if you want to improve your pull ups, even though OLy lifting is your focus, I would incorporate the jumping pull ups, assisted pullups, and other pull up variations into your olympic lifting warm up. In other words, I would go ballz out with pull ups pre-snatch or clean and jerk, but I would do a few to GTG at the beginning of the session, while you're fresher. The return to movements for full out sets after you've done your lifts and your primary assistance movements.
I don't know if that's something you'd considered or not? Don't even know if it's good advice or not?
All the best,