Without this mod, I can set the request threshold per item type instead of per station just using the base cybersyn mod signals and combinators. Do I lose that feature with this mod (as I can't figure it out) or if not, how do I make that happen?

Thank you

The per-item thresholds work the same as before. You place the station control combinator and send item signals to it, those will become the new thresholds for those items.

You could use this combinator to send those signals since it works like a regular constant combinator. But there's not much point since sending virtual and Cybersyn signals to the second station combinator doesn't do anything.

So my recommendation would be to use the Cybersyn constant combinator for your main station combinator, and then a regular constant combinator connected to the station control combinator for the threshold overrides.

Hopefully that makes it clear, otherwise let me know!

Thank you for your thorough response