As a user of all of MIDI keyboards, Grid controllers (Launchpad Pro MK3 and Linnstrument 200), and auxilliary MIDI controllers (Arturia Beatstep, Korg nanoKontrol 2), I offer the following comments.
I would quite like to be able to remotely control any aspect of Scaler that can be remotely controlled (e.g. Section selection, Section C row selection, Scale selection, etc.) easily and effectively from any of these devices. They all have utility for me, and in various situations for various reasons one device or another is the only truly effective choice.
For Scaler to accomplish #1 above as an enabler rather than a bottleneck, either CCs or notes need to be acceptable to Scaler as remote triggers - at the user’s sole discretion.
For Launchpads in particular:
a) LPs are ready-to-go with sending notes. Allowing Scaler to do switching on notes is definitely to be desired.
b) The user may wish to put 8 switches (e.g. for 8 Scales, or for 8 chord rows) either on an LP column or on an LP row. Clearly supporting an LP for with switches across a row is the easier case. Rows and key-octaves (as now) are sequentially the same ( with choice of All | White-Only ), whereas allowing columns would require the ability to define the entire map in Scaler in a new and different way, which is much more work.
Ultimately, Scaler may punt on supporting columns. If you don’t punt, then it may be far in the future before you get to that (in the face of other priorities). Mostly, I suggest just to be aware of the possibility of columns and try ton to do anything that would make it effectively impossible to support columns at a later time.
c) It is probably possible to write a custom driver to mediate between the LP and Scaler. This would allow you to use all the buttons on the LP device (not just the 64 play pads) in very creative ways. For example, see ‘Driven-by-Moss’ which is amazingly control of Bitwig Studio via custom driver. This approach. again, is much more complicated, but being able to use for example the Scene buttons in addition to the 8x8 play buttons would be super!
Short summary: allowing notes to act as switches, and keeping the current octave-zone/row correspondence, is the shortest path to Scaler supporting grid controllers in a good usable way. I suggest this as the next step, after which other steps might or might not someday pass the effort-to-reward comparison test!