This is possible, but it is probably more work than you expect.
Mock is not abstracted in the code, so you can't simply swap out mock for something else. You'd need to write new method handlers.
There is also the matter of how to trigger such builds. If this plugin adds new build methods, then you'd likely need a hub plugin to create the task(s) and a cli plugin to provide the command.
I suppose you could alternately override the `buildArch` method if your approach could work as a drop-in replacement for it, but it's unclear what exactly you are trying to accomplish.