I think theoretically there are no limitations, but it does mess up your notes' layout if you have used different formatting, handwritten notes or attachments (my notes in OneNote are pretty wild, I think).
However, at the moment there seems to be a bug resulting in some sections / notes not being imported. They are working on it and for most things it works great, but after importing you should check that all your sections / notes are there.
See here: OneNote ZIP import incomplete - #13 by againman
But, given that: I think the Joplin OneNote importer is the best tool for "getting out of OneNote" that I have found so far. The Obsidian OneNote importer e. g. simply ignores all handwritten notes (and I am not sure how it handles attachments). So as soon as the missing sections problem is solved, this might easily become the gold standard for people to leave OneNote to switch to a more open note taking software.