Is this known that you can warp away when you touch the poison in Tostarena? I just tried a few times near the Jaxi Temple area, and its not too hard to open the map right when you touch the poison and warp away instead of dying. It seems to be frame perfect though.

Yeah you can do the same thing in the Lost Kingdom, except one time I died when it happened: https://twitter.com/AteBallEight/status/929802872614674432

I think it's slower than dying

It's probably slower than dying but better if you're using the route without Sphynx. I also wonder if it works on lava or other special floors.

I've only done it in the lava where you take one hit at a time, like in luncheon. Never tried on the instant kill.