It's not an exotic idea but I would love to see a Master Output
module. At the minimum it should have four inputs with level and pan,
a master volume control and a master stereo ouput. Ideally it would
also include an integrated headphone amp with its own volume control
and some type of output metering (LED or VU). This would be
incredibly useful for putting together a smaller suitcase-style system
and it would also be welcome in a larger system for the sake of
convenience.

Replicating these functions with current modules would require 4
A-134s, 2 A-138s, an A-139 and 2 A-197s plus a bunch of unnecessary
patching. The end result would cost $677 and wouldn't even be laid
out in a logical and ergonomic manner. If such a module could be made
for around half of that price I think it would be an essential
addition to anyone's system.