Some of these features will need to involve DSP programming ....
For example, while simple stereo linked channels can be carried through to the LR bus via client-side only program mods, routing a stereo channel to a stereo Aux will require DSP programming to keep the left and right channels separate all the way through to the aux out (otherwise you get a pair of mono outs).
We have to assume that Mackie has a DSP programming team, or at least access to DSP programmers to continue with bug fixes and enhancements.
What I don't know -- and maybe someone else does here? -- is what limits of the DL's DSP are. From prior threads I understand that DSPs in general are extremely flexible in terms of placement/order of processing units and routing options. So adding more flexible aux tap points should be just as doable as creating a true stereo aux.