@Riley_S , Yes, I think you get it.  If I run a modem replacement, it will take the feed from outside into house; yet be in a passthrough situation. then if I get a separate router that can accept a VPN setup within it, that would be the combo setup.  However, if I was to find a Combo Router/Modem that can take the feed, allow for the AX1800 kit to work off of it on a separate SSID, that would be just fine.  As long as I can have 3 units use a configurable router that allows me to install the VPN for those 3 units, we can make this work; I think. :-)

The issue is having a router that can have a certain VPN installed into it, and that router will take the 3 units (Smart TVs)  that need to have it's use.  Software and separate SSIDs can be used to handle the rest; for which I do like what I think this kit (AX1800) can accomplish for everyday home usage in a concrete house.  

Should a new 'gateway' be used with this kit, and it offers 2 incoming feeds; that would be ideal. :-)  I did get a recommendation for an Asus RT-AX86U, but I haven't determined if it really does allow my VPN to be installed on it or not; and it looks like it would be router only portion, and would still need to get a modem.  However, I would like to check if TP-Link recommends any particular make/model to work with their mesh kits.

Thank you for pitching innto the conversation.

Tim

An update: I contacted ExpressVPN, and determined what router is flashable to be used with their VPN.  I found a router compatible, and it just so happens to have an accompanying combo deal for a modem.  So I can swap out the rental Xfinity combo gateway, and replace with an Arris Cable Modem and  the Asus RT-A86U Flashable Router as separate controlled units in the setup.

Then I can attach this new AX1800 mesh system with X20s for the majority of the devices, into the new Asus Router as the main determination of who uses the VPN, and who can passthrough as needed.  Not having seen the router software and configuration options, I can't be sure what will be the final product layout.

Gear to arrive Sunday, so by Monday maybe I can post an update.

Tim

Updated after setup.  I was not able to put the VPN on the router I purchased, so decided to hook up the new mesh with the same SSID and Password; and that brought everything up to speed and working.  Placed the 3 units in various places around the house to get coverage on the porch, patio, front workshop, and the whole house.  Seems to work nicely.

For the VPN, I have opted for software based on devices that need it now, and when I move and need to switch them, I will get whatever router at that time will work with a vpn as my front end, and plug the Deco main into that.

Thanks for the discussion on this.

Tim