I think you wouldn't gain much compared to a normal tohkbd, since the thickness would be about the same, and the tohkbd removable part will already allow running scripts using key combinations. This one seems to be more targeted at people who won't have the keyboard, or just want something simpler/thinner.

The "alternative keyboard" parts could of course be really awesome for some functions (fully removing a non-official OH is very inconvenient), but I think it wouldn't be very useful for shortcuts, since tohkbd will do that.