For my use case, I had I transitioned shapes over text to give the appearance that it disappeared. The shapes were the same color as the background, so for simple backgrounds that would work.

Maybe it's doable using the css pro feature?

Definitely need the option to make a fragment disappear i.e. create layers that feel like transitions. Sometimes you don't want to jump to another slide e.g. when you have a fixed image, but two fragments of text that you wish to switch between BUT you can't because the first fragment of text would stay beneath the second fragment that loads on top of it.

This forces me to make a second slide with the same fixed image, but with the second text. This is Really problematic because there is a transition in between which causes a jump, leaving only one (sad) option, which is: no transition.

I would expand on this a little bit: let fragments have a "beginning" and and "ending" number, with the latter being optional (if it's unset, the fragment sticks around until the end).