Knee tap/underhook combos if you extend them out, and use the "hip drive through" (you tuck your bottom leg under and start stand up forward, I call it a grappler's lift).
I love using the "Switch" when guys go to pass as long as they are low and trying to tie up your hips instead of your head.
Kin just watched the video, what if (on the first one) they are holding onto your hips/legs? I feel like you need to frame against their neck or shoulders to create the space otherwise they are just too strong for you to scoot your hips back or they'll have enough time to switch to that over/under to pass.
Even when they reach under my unhooked leg and grab my foot or my pants by sitting up I turn my hips over and reduce the profile so much that when I push I almost always pop out far enough to reinsert my hook or plant that foot on their bicep to help strip my other foot free.
Now, if instead of pinning my legs with their elbows they have already beat me to the punch and starting hugging under my hips before I could sit up then it's omoplata time for sure. I push the head HARD to the side they want to pass on and bring my unhooked foot up as hard as I can while pushing hard to get ninety degrees and rolling up on my side facing the direction they want to pass in.
I will say I have not had anyone successfully switch to that over under pass against my butterfly guard in the last two years simply because my immediate reaction is to sit up and grab across their back.