hard (like omen slayer title, getting an abolitionist title, etc), tedious (diving spots, fleets, athena pages, professions, note appraisals, etc), or superfluous (nearly all of the logbook stuff) features should be tied to the person, not the file.
I’d also like something like syncing total hours (or atleast having a total hours stat somewhere) but dont know if thats easy to implement or not
If the syncing of the professions too hard (or if you want to implement something simpler first), at the very least grant a 2.5x (or higher if possible) experience modifier to professions you have reached level 10 on (you can easily achieve this via having badges for achieving a specific profession max)
Something else i’d like to have switching FS/magic not make you lose your abilities, or at the very least make reaching max mastery on a FS will permanently master that FS, so next time you grab the FS you dont have to grind the FS to unlock the moveset.