That's all implemented now so you can try it out and let me know.
right click Save Link/Target As
ReaTrak create midi scale (snap guide).lua
ReaTrak create midi scale (snap guide) (Lokasenna GUI library).lua
It will use the current or last used Reascale in the Midi Editor,
it will name both the item and track with the key and scale,
if the Key snap is currently enabled in the midi editor it will give the reascale name else it will use "Last Reascale".
I set it so you select the time selection the whole song or part if the scale changes.
It already creates a chord snap guide if you look above, the root is green and the other notes yellow when the midi editor is set to color notes by channel, see pic below to use color notes by Track.
Here's the new snap midi to chords you can try, don't use it from the button just run the script it's self, It will snap a single item in one hit, just select the time selection, select the track and run the script or hit the Snap MIDI Items to Chords button.
It will do a single item or multiple items on a track.
I will update them in the next ReaTrak version.
Thanks to Lokasenna for Reascale to ix_scale script and the GUI.
ReaTrak snap midi takes in selection to chords.lua