What I meant is that a user can choose per filetype which of the configured commands is executed automatically. For example, for C I might want the "Compile" command which starts `cppcheck` or whatever but for Python I would rather the Build command executed because I configured it to use the linter. This would give more flexibility. Though this is of course a bonus and doesn't need to be available in the first place.
Anyway, let's hope someone feels encouraged to give it a try and implement something cool.
So, in summary new plugin should be 'run on save' which would be able to run custom command per filetype after save happens. I wish I could be the one who write it. But my skill is limited as I only know c,c++ with 0 knowledge of gtk. With a mentor I think I would be able to implement that plugin but that's an option, may never happen. In that case, allow me to request for a plugin in the plugin, let's see if we get any good soul who implements it.