Maybe someday if I ever buy a Mac so I actually export the game for Mac.

That's not quite how it works. After you progress past a certain point, newer scripts that weren't available in the older version will no longer trigger if you load that save file in a more recent version, which can potentially cause bugs, like certain characters or objects not showing up in places they should, which then can result in quests getting bugged. I can't tell you for sure how save files from 0.18 will do in (I assume) 0.22. You might get lucky, or you might not. Generally speaking, the less progress you've made in a save file, the less likely it is to cause problems in newer versions, since Spedumon normally doesn't change older areas of the game anymore.

Spedumon did work on one at some point, but it was too time-consuming, especially since JoiPlay works just fine.