I've designed a block that uses an external javascript library, which modifies the html structure. So I have to use the cleanForSave function (in a snippet options javascript file) to destroy the instance and undo all the DOM modifications before saving the html.

I would need a way to call that function (or a "hook") before saving in editor mode, even when the said block has not been edited/added (so the onStart/onBuilt/etc. functions have not been called).