MKII will only run 2.10 and 2.20.
I'll try the "new" 2.20 on my upgraded MKI unit and report back.
Either way, this is possibly good new for the newer MKII units. A friend on mine had been in contact with Paul regarding issues with some PWD MKII new units. Supposedly Paul admitted that a few of them needed a digital board replacement. I know that a newer MKII unit I obtained sounded like donkey when directly compared to the MKI upgraded to MKII. Little bit less resolving, less microdynamics, but most damning was lack of low bass response. Maybe Paul got wind of this issue and put in a fix.