... For basic use I can see that using the MIDI channel change might be efficient, but my String template (for example) has 44 articulations loaded. I wouldn't want to be limited to only 16 of these. How would one get around this?
One would get around that by using the articulation-change options VI has been providing all along which aren't tied to MIDI channels, as the MIDI-channel specification is a relic designed in 1982 to accomodate slow cables and 8-bit CPU's.
That setting in Logic is for MIDI Channel. There are 16 MIDI Channels, as was decided in 1982. If you use that Logic setting, you get 16 choices, not 44. Logic could add another setting right next to it for Articulation, not limited to 16 choices; but that's off-topic I suppose.