PnP or not is all about how resources get allocated. Assuming non-conflicting resources are used that the software you want to run supports, it makes no difference whatsoever whether those resources were allocated via PnP or not.

It's all about the road there. With PnP you have to trust that whatever is configuring your card does so correctly. In the past that was a hit-and-miss crapshoot, with early PnP BIOSs being brain-dead and the card manufacturer-supplied tools inconsistent at best. These days, Unisound supports most PnP sound cards and does so so well that you have as much control as with jumpers, just with less messing about.

As for the ES968F itself providing PnP services - I'm slightly sceptical (in absence of datasheets) as it was supposedly just an effects processor. But I've seen that claim in other places too - although my Russian isn't hot enough to be completely sure about this: https://www.arvutimuuseum.ee/sannata/DG_magaz … owngradeN28.pdf

For what it's worth I have two cards with the ES1688. One with the ES968F and no jumpers, and another without the ES968F and with jumpers.