Have you tried using a midi track for PC messages?
First you disable the PRG CH SEND (under system, config, sync) and then you use a midi track to send the PC messages instead.
The upside is that you can select what PC message number to be sent (pattern 1 doesn’t have to send PC message 1 to the Digitone) and you can choose to send the PC message on a trig late in a Digitakt pattern so the pattern change message arrives nice and early for the Digitone.