Yes - the NG design has one large DOUT and one DIN chain, each with up to 128 pins, and a definition table which allows to define the function of the pins. The chains will be served/updated every 500 uS so that they are (in addition to buttons/switches and LEDs) fast enough for encoders, LED rings, LED digits, etc. in mixed configurations - the reason why this flexibility is not provided by the 16F designs is the limited memory…
from my experience pseudo protocol structures like known from commercial controllers don’t offer the flexibility like the simple Meta events concept. With the Plug-In capability (code can be downloaded via MIDI) updates of Meta events will be easier than ever before and therefore I will stay by this method.
In other words: yes, will be supported - (really) any MIDI event strings will be programmable.