Rope skips with the beetle enemy set are actually pretty easy and forgiving. I think only the first 2 are possible. The second beetle spawn needed for the second gap seems to be RNG if it will spawn or not.

The "trick" is to jump very late in terms of the ground. You want to do a jump that is technically off of the platform (similar to the jump used when grabbing the scrolls, but attacking is unnecessary).

If you jump late enough, the beetle damage boost is actually very forgiving and you can even press back a bit if you think you aren't going to be hit by the beetle.

After you make the skip, avoid the white pillar, as touching it will activate the rope throw back to where you came from. Just jump over it.

First skip seems to save about 1 second, the second skip saves about 2 seconds.

I think we all knew this was possible, but I thought I'd play around with it a bit. Wouldn't surprise me if timing varied from RNG, but I think since you wait for him to spit fire, it might be possible to be consistent.

For the second pit I used the head again and I think it takes a similar amount of time to set up as the beetle. Killing the head to get back to the beetle set is pretty easy, but either I had bad RNG or this setup ruins the forward moving beetle spawn, as I just can't get it to appear in this save state.

edit: Confirmed it was bad RNG. You can get a forward moving beetle for the second pit.