After discussing with @zemarmot , it turns out you can get non-destructive editing in #GIMP by commenting out two lines of code. :)
Now that we know the basic structure is there, I need to review the code to understand how to implement this properly (GIMP assumes all filters are merged after applying, so that has to be fixed in several key spots).
@CmykStudent @zemarmot
For painting tools, it should also be a matter of recording all keystrokes (and their parameter) in a list - always looked luke feasible for me.
There is even a W3C standard with a XML for it, we could use fo serialization - InkML ( https://www.w3.org/TR/InkML/ ) - though, maybe, there are less verbose forms.
@gwidion @CmykStudent @zemarmot could be a useful import/export option. Not sure about XML as a native format tbh.
mastodon question: when we boost a post from other server, does it go to the local instance timeline?