I don't see any reason why the ability to change the GUI would be seen poorly. The addition of "local variables" would be very handy (coulda used a variable for grenades in AD).
It seems I read that too fast, and misunderstood what you meant by "local storage" (although I do like that too). Just basically "another EP", but that can be named differently, etc. So instead of energy on a unit, we might have ammunition and grenades, which could have separate regeneration rates. Not really related to the UI besides the fact that it would be displayed there too.