Using Midi Controller on 4 Elektron Machines – #3 by JacopoAcquafresca – Elektron Gear

The Digi boxes do not forward CC messages as far as I know. They didn’t do it some years ago at least when I tried to do something similar with a Keyboard synth, DN and a Nord Drum.

I think you will have an easier time if you rethink your setup with parallel MIDI connections. Instead of going from one device to another in series, you would use something that acts as a central hub.

There are basic MIDI splitter boxes that take one MIDI input and replicate it across several outputs.

There are configurable options like the Blokas Midihub that would allow you to process, filter and route the MIDI messages, so that you could send notes and/or CC to specific MIDI ports based on the MIDI channel and a ton of other things.