Not offering the perfect solution you were looking for, but if you’re still using the ISP router it might be worth it to upgrade that to something you can install custom firmware on that’s also relatively cheap like an asuswrt-merlin compatible device (I personally use an ASUS RT-AX86S).
That would allow you to have a guest wifi using YazFi that routes everything through a VPN of your choice and it would leave your regular wifi untouched. You can even use the DNS director to intercept all traffic on port 53 and reroute it to your pihole, including queries going out to 1.1.1.1 or other public DNS servers from apps trying to circumvent DNS blocks.
Not offering the perfect solution you were looking for, but if you’re still using the ISP router it might be worth it to upgrade that to something you can install custom firmware on that’s also relatively cheap like an asuswrt-merlin compatible device (I personally use an ASUS RT-AX86S).
That would allow you to have a guest wifi using YazFi that routes everything through a VPN of your choice and it would leave your regular wifi untouched. You can even use the DNS director to intercept all traffic on port 53 and reroute it to your pihole, including queries going out to 1.1.1.1 or other public DNS servers from apps trying to circumvent DNS blocks.