Ah, I must be looking at the wrong docs then - it does make sense to have a unified api for shared attributes; I concur. Please let me know the correct link and I shall bookmark that to avoid bothering you needlessly again.
I was thinking of putting it on a dongle but the issue is figuring out how much length I'd need and how to stop the antenna of the Feasycom flopping about which I imagine could do more harm than good for the signal quality. As the network interface is only 1Gb/s I think ~1/2 that speed isn't a game changer, just an annoyance for now. The drive is mounted as exFat for interoperability/easier data recovery so the speeds were never close to full gigabit anyway. Long term I'll move to a pi 5 with an SSD attached directly over PCIe which should mitigate the problem entirely without needing to mount cables on the wall or add more shielding (I hope!)
I should add that with the aerial working normally without USB 3 interference I'm seeing much better range than I expected. I tried out using BTHome on my Bangle JS and it was picked up in the 2nd floor bedroom through two different floors! Seems to pick up ThermoPro thermometer units just fine at that range as well.