I am aware it is already possible to directly add Z-Wave devices to Home Assistant and then from Home Assistant share them to HomeKit. However there is now a device from Thinka which takes Z-Wave and shares them to HomeKit, what’s more this is currently unique in being the only official Apple certified way to do this for Z-Wave devices.
Would it be possible to link Home Assistant to this Thinka hub?
If Thinka ever added Matter support that would be one possible approach, but are there any Z-Wave slave/master hub options or direct IP approaches that could be used?
I don’t think that would help in this case. Yes there is also a Thinka KNX to HomeKit bridge and it might be able to link Home Assistant to KNX but I am specifically talking about the new Thinka Z-Wave to HomeKit bridge and as far as I can see there is currently no available integration between this new product and Home Assistant.
You could add the HomeKit devices as exposed by this Thinka HomeKit bridge to Home Assistant and re-share them as HomeKit from Home Assistant but that clearly would be perverse.