+1 for switchable midrange response. I know people tend to look at weight as an indication of portability, but handle placement, weight distribution and box shape have as much or more to do with it. OTOH, this response smoothing function might be more easily and flexibly incorporated at line level via a box/pedal in the effects loop. It could also include a low bass boost tailored to the cab (and its capabilities -excursion limits). This approach might be more cost effective, incur less weight penalty and allow for future upgrades. It would also allow players to switch in those response changes 'on the fly'. Just an idea
OTOH, maybe it's a good idea to just keep things simple, and incorporate theses changes in the cab as you planned.