Go for 3. It’s a pain to get out of CGNAT on EE

Change the APN to 3internet on whatever board / modem you use and that should see you right for failover. I’m not sure you to config that on your particular HW though.

Right ???

I think the easiest thing to do would get a used 5G hub from the likes of fleabay, setup the BSD box for link fail over. What distro are you using ?

For double NAT issue getting a real IPV4 address is a chew using regular data Sims. The only one I’ve had long term success with is 3.

Sorry, I’m assuming your UK based ?

I’m one of those people into Omada. Yes it’s not sleek and shiny like unifi but it does an incredibly similar job for a cheaper price. Reliability has been very good for me. No returns or issues yet 🤞

For you I’d start with https://www.tp-link.com/uk/business-networking/omada-router-integrated-router/er7212pc/ it can easily be hidden away.

Add a https://www.tp-link.com/uk/business-networking/omada-wifi-ceiling-mount/eap650/

And / Or

https://www.tp-link.com/uk/business-networking/omada-wifi-wall-plate/eap650-wall/

And your away. Add another any APs you need to the POE switch on the router.

If you want recommendations on a switch let us know how many ports you need.

Your just pissing cash in the wind buying ancient HW like that. Why are you so keen to get WRT ?