After experimenting a bit with this awesome tutorial for lightning bolts: youtube.com/watch?v=C5g3Zdvitg4,

I found myself on this Github issue: (github.com/godotengine/godot/issues/87843)

Fortunately, there is a nifty tool in godot to convert from GPU particles to CPU particles, and actually there are a lot of "hidden" tools in that bar! Like stuff for generating outlines for meshes and other fancy stuff!

Hope it helps