Ideally, there would be a wired HomeKit secure video option, but I have yet to see it.
Scrypted supports quite a few cameras, doorbells etc...
How?
I was under the impression that you cannot actively decide which device becomes the primary one?
I 'only' got a wired ATV and a HomePod mini - and the mini is the primary hub way more often that i'd like it to be (like... none of the time, at all :) )