Will HomeKit remote access still work if I add a VPN to my Apple TV? I've currently got a great little HomeKit setup in my home which works perfectly even when I'm out of the house. I understand that HomeKit makes use of the Apple TV as a hub to enable remote access to my home.

I'm considering purchasing an ExpressVPN subscription as I live abroad and would like a reliable way of accessing TV shows without having to constantly find new VPNs. I understand that ExpressVPN is unlike many other VPNs as it provides the option to add a VPN directly to the Apple TV as per these instructions.

However, before jumping at the opportunity and shelling out a rather steep price every month, I thought it best to check the consequences of such a move.

My question is: Will my HomeKit functionality stay the same with a VPN on the Apple TV? 

In other words, will I still be able to remote access my home kit devices while I'm out? If not, what are the limitations and are there any mitigations? If so, would there be any other unforeseen consequences of adding a VPN?
Your VPN connection isn't really a factor since all the of the synchronization is done via iCloud.

To simplify this a bit, consider that to remotely control your HomeKit (via the HomeKit hub), your devices must be signed into iCloud with your AppleID.  When you're away from home, you're on a different network and control your HomeKit devices.

A VPN is nothing more than a secure way of connecting a computer on one network to another so that it you're actually on that network (i.e. you're in Paris, France, but you VPN into a network in New York).

So, whether you're on a remote network or on a remote network but connected to a VPN, so long as you can sync with iCloud, you can control HomeKit devices.