Add AddParent/RemoveParent to API

I'm creating a new plugin Playlist Manager. One feature I was hoping to do is Add/Remove Parents for the selected playlist. e.g. Remove from Arcade (Platform) and add to Arcade (Category). (un-check and check respectively as seen in Edit Playlist - Parents tab).

Unless I'm missing a [better] way via the API, I need to edit/amend the Parents.xml file accordingly, then use the ForceReload() method. (Not ideal. But feasible. [At least "on paper". Not tested])

I'd like to request adding API calls to be able to AddParent/RemoveParent. Include for Platform, Platform Category and Playlist.