Can upgrading be made to work via DnD?

[twMat]

I know it is not possible to straight off DnD a new core plugin into an old wiki to upgrade it. But...

1. could there be a "wrapped core plugin" to make this work? I.e some additional stuff that, when dropped, kicks in to pull the necessary strings?

2. ...what about if the user wiki is hosted in it's own environment like Tiddlyhost? Could this environment soften up the dump to make a dropped core plugin fit? (Currently, upgrading on TH adds even more steps to that of upgrading a local file. Basically, the user has to leave his wiki to go to the "Your sites" page, therefrom export the wiki, then do the standard local file upgrade steps, then upload and go to the wiki.) I figure the environment could basically do programmatically what the user has to do locally/manually.

Or is it just fundamentally not possible to drop a core plugin onto a wiki to upgrade it?