I didn't know about bookmarks, thanks.
I'll still continue to use skuroda's plugin for three small reasons:
-By default, you can only see the lines on which there are bookmarks, and not the column.
-I find it more natural to "leave cursors", move the cursor to the last place, and write from there. What happens with bookmarks is that the "not saved" cursor is deleted.
-If you accidently pressed "Select All Bookmarks" (which I would have binded to a "faster shortcut") without any saved bookmarks, the cursor would be deleted, and you would have to move your hand to the mouse and click to create a new cursor.
The two last "issues" were actually initially present in the plugin too, but fixing simply required changing
elif action == "show":
by [code] elif action == "show" and len(self.saved_cursors_map[view_id]) > 0:
for cursor in cursors:
Anyways, thanks to both of you.