According to the manual, if you want to set a user microtuning, you tune each note of the keyboard. You can play up to 4 notes (max polyphony) and thus tune up to 4 notes at once. Tuning is by +/- cents from the nearest equal tempered note. I guess you’d have to use a calculator elsewhere to convert Hz to cents if your scale is notates a Hz values.
On a related note I can’t see in the manual if sequences can be transposed by playing different keys on the keyboard, as you can on the Monologue. I suppose others have taken a look at the manual and also arrived at the same conclusion.
Manual page:
https://www.korg.com/us/support/download/manual/0/811/4216/