I'd like to try and resurrect this thread. I have a couple of JL Cooper interfaces on their way, an MCS-3800 and MCS-3000XL-SA. Much of the function (including fader and LED feedback) can be handled through CCs possibly from the midi learn function within Reaper, but the tighter integration I'm looking for uses sysex messages. Specifically, the 3000XL has backlit LCD buttons per track, which can dynamically display track names, arming status, etc. I understand that without the sysex strings, I'm pretty much stuck. I have contacted JL Cooper about this, and their response was that the sysex functions I need are only available to partners/developers....
Using the Pyramix demo (which supports all functions of the MCS-3800), and the MCS5 manual, I believe I can sort out some of the sysex that is useful to me. According to Pyramix tech support, the 3000XL-SA is only supported as the 3000X (which does not have the buttons), so I still can't get there from here. I should be able to get the sysex strings for dynamically naming/updating the LCD in the transport section of the 3800, which is a nice first step.
If I can get my hands on the sysex, I will likely need to use OSC to retrieve the proper information (i.e., track names) from Reaper and send those as sysex to the controller. I'm not sure this can be accomplished via midi from within Reaper.
If anyone has interest and/or energy and/or expertise around this, please post. Thx.