The risks? Save game corruption due to duplicate FormID spam within the save game(according to FF7Legend). Not sure what your second question is about. If you mean updating 43 to 44 only creation kit can do that properly and usually only one at a time since it often crashes when trying to load more than one .esp in a single session, even with CK fixes. Simply load the plugin, save and exit, profit.
It shouldn't "break" anything since it doesn't compact FormIDs(or does it?) unless you specifically choose to do that for converting to .esl or esp-fe(.esl flagged .esp which won't count towards the 255 plugin limit), that will need a new game
That being said I'm not a mod author and you shouldn't take any of that at face value, that's what I read from more knowledgeable sources. I'd simply avoid downloading from irresponsible authors like PRJ and YoerkSun and demanding that they fix their shit or report them to both Nexus and Patreon(not sure if that'll help but who knows), but to each their own