Hey, i don’t have a mac, so i cant point you the location of asset store folder. You should try to search it yourself
Basically everytime you download a package from asset store, it is store the file on it.
If you do fresh install, you will lose all the actions that you downloaded from ecosystem. You could backup the playmaker action folder before deleting the old version. But some actions are included in the new playmaker. So you might get duplicate warning
Good luck