Physical effects loop! For Ampli-Firebox... This could be individual send/return, or TRS to save space. Ideally, the loop would be switchable in/out per preset, and primarily be placed between the AMP and CAB. The assumption is that the loop would be used primarily for time-based effects (think H9, Timeline, Holy Grail, etc.) The other assumption is that dirt pedals could be placed in line from guitar to the device. This would be simple, and awesome.