Although a third page for synths sounds good in a first impression, thinking a bit further I wonder in which situations people will hit a limitation with the shared page for MIDI & synths. There are eight tracks, every track can carry different MIDI values and synths, and every pad can produce a chord if needed. There might be a reason to fill 8 pads for simultaneous audio coming from MIDI and synths (plus 8 for samples, that’s 16 simultaneous sound sources)… like very thick ambient textures or very complex polyrhythmic structures… orchestral music?
Three pages also means more moving around and more effort keeping in your head the actual structure of the music you are producing. Two pages means, one for samples (which is a type of behavior) and one for synths (local, MIDI, up to you).