Remote devices do not have that limitation. In my opinion, sending commands to windows that are not visible, or not frontmost should remain the domain of remote devices, except in certain cases, such as File>Save and other global type commands.
In regard to metagrid, in that other thread there does not appear to be a clear understanding of how it works. Is it MIDI? Keystrokes? By what method does it determine which window it is sending to? If Metagrid can’t send a command to a particular window, how is it up to the SB team to sort that out?
I say this, because I use autohotkey, which reveals that it is indeed possible to specify which window a command should go to, to exclude windows by filtering various parameters, etc.