Adding a scaffolding function would be nice

[R-J]

Something like "vanilla create keyname AddonName" with the optional parameter --addon-type=[addon|theme] and type=addon being default,

There is the boilerplate theme which would make a good start. There are not many manual steps before the final "vanilla build" for the boilerplate theme, so this is no big effort, but it would make the tool even more versatile.

For scaffolding addons a minimal folder structure should be created with nicely named plugin file, js and css files, an icon file, some default methods (setup, structure, ondisable, assetModel_styleCss_handler for including a dummy css file and a base_render_before for including a js file)