To share the benefit of my rainy day progress on this issue, I am pleased to announce that in Sonar X1, I've gotten past the 'Connecting' hang, with my Behringer X32, and have made some baby steps toward useful function. I am running on the Firewire interface of the X_UF through a PCI Texas Instruments adapter.
In the Behringer X32, the 'Setup>>Remote' screen has...
Protocol = Mackie Ctrl
Interface = Card MIDI
MIDI In/Out = Card MIDI
Remote Button = Enable {toggled orange}
In Sonar X1d, the 'Edit>>Preferences>>MIDI>>Control Surfaces>>Connected Control Surfaces/Controllers'...
The 'Mackie Control-1' selected and X_UF MIDI for both 'In Port' and 'Out Port'.
WAI is checked, and I picked yellow for my color.
Under 'WAI Display', 'Track View' and 'Console View' are both checked.
I opened a 30-track project, and under 'Utilities>>'Mackie Control-1', there is an utility edit dialog box. This utility seems to be a holdover from a Sonar 8.5 installation. It says Chris Boucher [chris at sorted dot org] copyright 2002-2006 along the footer of the dialog box. In the bottom right-hand corner of the box, I picked 'Fader touch selects channel' and 'Select highlights track'.
The biggest leap forward was choosing 'Meters // Signal LEDs + Meters. That made the meters work in the X32 bus faders. Back in the X32, I tapped the 'View' button in the 'Assignable Controls' area.
Within Set-B, I chose...
Select Control Button 5 /// Remote /// < Bank
Select Control Button 6 /// Remote /// > Bank
Select Control Button 7 /// Remote /// UP
Select Control Button 8 /// Remote /// DOWN
Select Control Button 9 /// Remote /// REW
Select Control Button 10 /// Remote /// STOP
Select Control Button 11 /// Remote /// PLAY
Select Control Button 12 /// Remote /// FF
I put some other stuff in Set-A and Set-C as an experiment, (for example, RIGHT and LEFT moves between markers), but you get the idea. The faders work, but their current position value in dB isn't displayed in the little display window for each bus on the X32 as Studio One does; I only get a sequential number 1-thru-8 in that field. Fader responsiveness also seems a bit sluggish compared to Studio One, but for now, I'm overjoyed to have gotten this far past 'Connecting...'.
The Studio One 2.6 support of the Mackie Control emulation in the X32 is my benchmark for function; although I haven't figured out the equivalent of WAI marking in that DAW. Conversely, Logic in OSX does the WAI very well on the X32, but defaults the fader position value to zero after you stop moving the fader.
That's the extent of my baby steps. I'd still like to see what differences there would be with the MackieControl.dll from X3c, but at least there's marginal function at this point.
I hope these "instructions" are helpful to someone.