Marbles Firmware for Custom Scales

Hi All,
Would it be possible to alter the Marbles firmware so that the custom scales input mode would latch on?
I would like to be able to quickly change the notes through a keyboard on the fly. Say, give it CDEFG for 2 measures, then quickly give it CDEbAbB for a couple measures.

Could the module handle real-time changes like that?

How easy/difficult would it be to change the code to do that?

Thanks for the help.