I currently have a FF800 and am thinking about upgrading to a UFX, and then use the FF800 to expand the UFX via ADAT.

I also am considering getting a Mackie MCU Pro. I would like to be able to control the UFX in 2 different modes: Standalone, using the Midi input to the UFX (this would be when my DAW PC is turned-off) and via USB into the PC controlling TotalMix when the PC is turned-on.

I think I remember seeing in another question/answer posted in this forum, that the MCU Pro could not be expanded with the Mackie Extender Pro for the purposes of controlling the UFX in Standalone mode, ie the only way to control more than 8 channels is to bank-switch the 8 faders on the MCU to other groups of 8 on the UFX and its ADAT inputs, etc. Is this correct, ie no ability to use the Mackie Extender unit when the UFX is in Standalone Mode?

How about when the MCU is connected to a PC via USB -- Can it then be expanded with 1 or more Mackie Extender Pro(s), so I can control TotalMix setting the mix levels of all of the UFX channels and my additional FF800 channels with 16 or 24 faders? Also, if I am running the TotalMIx GUI on the PC and I use the mouse to move faders on that GUI, will the MCU & Extender motorized faders track the commands I am giving via mouse? How about Vice-Versa, ie if I move faders on the Mackie units, will the TotalMix GUI faders move/mirror my manual changes to the mechanical faders?

BTW, I generally only intend to use the MCU and TotalMix in these modes for controlling monitor and headphone mixes. For mixing after recording, I would just use the controls in my DAW to set gains, draw envelopes, etc using the mouse. So, most of the time the MCU faders would be sitting at a statically set position once I have the monitor mix setup. I do have to occasionally change / tweak the monitor mix while a recording session is on-going, being careful to do this subtly so as not to throw-off the performers.