Mono sum on one UR28M output

I have a single Avantone cube as an additional monitor to check mixes. What I’m trying to achieve is to have a mono sum signal sent to it via one output of the UR28M, without having to hit the “mono mix” button everytime I switch there. On my previous audio interface it was possible to set this in the control software, but I couldn’t find anything similar for the UR28M. What’s the best/easiest way to approach this? In case it’s relevant, I’m on OS X 10.6.8, and I’m looking for a solution that works with any DAW.
Thanks in advance for your advice!

I think you’ll have to set this up in the respective DAW - define your mono out channel as for example mix2 L. You’ll then have to set the output mode of the UR28M to Independent instead of Alternate.
I myself however route one of the mixes through a mixer console which has a separate mono sum out. In my case however I use it to feed a sub woofer, but the principle’s the same. Of course you may not have this luxury, so try the aforesaid suggestion. The thing to understand with the UR28M is that your targets, or outputs are the 3 mixes and not the actual physical outputs of the device.

Hey BriHar, thanks for your answer. I think I’m a step further, but there’s still a roadblock. So I set the output mode to “independent”, as you suggested. The cool thing here is that now, when I press “Output B”, it remembers to have the “Mono Mix” button on, so I wouldn’t have to press it everytime.

Now about the roadblock.
Since Output B saves the Mono Mix setting, this is the behavior I would expect (based on the routing diagram I attached):
I route the DAW to mix 1, and to no other outs, and the Output buttons on the UR28M should let me choose the individual monitors, with Output B having an automatic Mono Mix engaged.

But this is the behavior I get: On Mix 1, all monitors are active (with the cube getting its mono mix), regardless of which Output button I press. But I do get changes with the UR28M Source Select button. When I switch the Source Select to Mix 2 or 3, I get only Output B.

I don’t get this behavior, is this what it’s supposed to be doing? Like I said, based on the attached diagram, shouldn’t I still be able to select individual outputs with the Output buttons?

edit: I just tried muting the master tracks for mix 2 and 3 in the control panel, but I still get the behavior described above…
UR28M routing.png