Incoming MIDI data from unassociated devices still gets sent out in 2.1.3

Question

The problem I have reported numerous times for previous versions of MainStage is still present in 2.1.3.
An incoming MIDI CC value that is NOT associated with a device is being sent to other channel strips. Last night before rehearsal, I added a Minimoog XL into my rig. It's connected via its own MIDI port on a MOTU 128 Express. I discovered that when I turned the Vol control on the Minimoog, it sent out CC 7 and CC 39 (LSB values for volume) messages to a channel strip associated with a VocalLive voice processor and had absolutely NOTHING to do with the Minimoog.
As reported before, this also happens for CC80 and CC81 and I cannot see any reason why such events would get sent out to other channel strips if there is no explicit mapping defined. 
I had to add in new dummy knobs to explicitly block these values, further polluting my layout, which is already full of knobs defined just for blocking stuff.
A generic MIDI device set to listen on all inputs and MIDI channels with output blocked does NOT stop this from happening.
More details are in these older threads:
https://discussions.apple.com/message/12572359#12572359 and with more detail (including how to reproduce) at
https://discussions.apple.com/message/15483068#15483068 is still present in 2.1.3
(I've already submitted this at the feedback link (which, by the way, has no entry for 2.1.3 in it) but I am quite pessimistic about this getting fixed, it has survived many versions of MainStage....I don't understand why)
This is so disappointing.

Answer 1

That's partially why I'm so concerned about this --- I cannot conceive of a scenario where this behavior makes any sense --- essentially some external synth can generate arbitrary MIDI data which just goes out through other channels, and that data is at best of no interest and at worst can actually screw up the receiving device (which happened to me when my Korg Oasys was sending out CC80/CC81 as part of a program change and it was changing a parameter on my Minimoog)
It seems to me that they could have fixed this quite easily by providing (perhaps an extended version of) a MIDI Device that REALLY blocks everything so users with the problem could just throw that one gadget into the layout instead of having to make a bunch of knobs to block all sorts of things.