Thanks, that's a significant detail. It also seems like Bluetooth 5.4 adds nothing relevant to my expected use cases: https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/whats-new-in-bluetooth-v5-4-an-overview

Is there such a thing as a particularly good PCIE -> m.2 E key adapter or are they all pretty much equivalent? Specifically, are some antennae better than others or they're pretty much simple enough devices that they're going to be equivalent if they're remotely aiming at the same spec?

Unfortunately, it seems like Intel may be a bad bet in terms of use as an AP:

Intel cards are only usable as access points either in the 2.4 GHz band or (very rarely) on channel 36. This hardware restriction is stemming from the fact that they don't have the circuitry required for reacting to radar pulses, and therefore rely on the "proper" access point to tell them about radars.

Also it needs a USB header on my motherboard as apparently the BT aspect is based on that bus. So perhaps I'd be better off with a fully USB adapter, I wonder if there is a downside to that approach... Edit: PCIE is the way to go