Change sequence master output channels (2 → 8)?

I’m building a UXP plugin for Premiere Pro (v25.6.x) to create a clean copy of a sequence with stems.

Is there any UXP DOM/API to change a sequence’s Master/Mix output channel count from 2 (multichannel) to 8 (multichannel) programmatically See image.

If it’s not possible: what’s the recommended workaround in UXP? I haven’t been succesfull witj copy/pasting all content from a 2 channel sequence to and 8 channel one via UXP.
Thanks, Joost or run a command/action)?

@bbb_999 do you have a suggestion? Thanks. Joost