@VSK-11 

A VPN is not like dd-wrt. DD-wrt is like the user interface that comes on the router from the manufacturer.  When you install a VPN on the router is does cover all devices.

See https://www.pcmag.com/opinions/should-i-use-a-vpn-on-my-router for more info on the subject as it can cause some issues.

You can use any range extender however if the router you get supports MESH and you want to use MESH, then you need an extender that supports it also.

See https://www.tp-link.com/us/onemesh/product-list/ for a list of MESH supported devices.

I am not 100% sure about home shield but would think so since the extender and it devices are in the router pool of devices.

@ArcherC8 

Thanks for the reply. Yeah i'm no expert but it's 'flashing' the router to be able to replace the native firmware with dd-wrt, tomato etc. I have done this before, mostly because I really needed options that allowed installation of a VPN - ideally openVPN client on the router itself so that I don't have to monkey around hoping that my smart home stuff have apps that support openvpn configurations (most of them don't) - this is why I am particularly happy to learn of the AX90 - it allows this without needing to worry about buggyness of third-party software or compatability with third-party firewalls. I actually find its features impressive for a consumer / prosumer grade router/firewall. The homeshield is like icing on the cake.