If it can be contolled via OSC (as Peter mentioned above) AND if there is a tool to convert OSC to SYSEX for the Mackie's (such a tool exists for the Behringer X32/WING mixers) then your other option would be to work out the SYSEX command equivalents, and then use a 3rd party app (e.g. midiflow on iPad) to perform MIDI command remapping, and create a bunch of MIDI commands (e.g. CC changes) that you use in ST, and the app remaps to the prescribed SYSEX command.
Convoluted and time consuming. But it can work.
ST4 will support SYSEX so the effort still has value, and becomes a little easier, in the future.