DNS in routed pi 3b+ VPN wifi repeater

Hi guys,
I travel quite frequently and have a hard time getting all my devices connected nicely and easily with restricted hotel wifi or public areas. A vpn connection to home lan shall be availble to all of those devices. I have the server at home, I have bought a Pi 3b+, installed openwrt on it, and set it up as dualband wifi repeater. It works till here.

My questions are a bit more complicated. And yes, I know there is a ton of advice out there with hundreds of scripts and tech terms I dont understand. So I hope you can help me getting this to work.

My issues are dns related after VPN connection has been built. At home I have my own dns server running on FreshTomatos. It is having its local domains for local devices in LAN bridge. I want to use this dns at home over my VPN.

So first topic: can I use openvpn as a standby vpn solution, if the public wifi is blocking my wireguard port? Wireguard is using UDP and this proto is often blocked. Can this be installed in such way that I do not need to orchestrate the failover to openvpn? I simply want to go for: as long as wireguard can connect to my home server, use this as prio. If its port is blocked and no connection possible, route my traffic over openvpn.

Second question: can dns requests follow the same logic as question one? I have set the customDNS option in wireguard interface, but it is ignored so far. As long as "Use DNS servers advertised by peer" is ticked in openwrt wwan interface, domain names known only on my home router are not getting resolved. If I untick this option resolving those local names work but I have often problems to build up the vpn connections, because a vpn needs an initial dns request to get the ip of my dyn dns domain.

Can all this be done without any script and purely in LuCi?

Thanks guys for any help. I am loosing a lot time trying things out without knowing how this should be done.

Yes it can be added with Luci.

Back up what is working for the most part.

You can look for the pkg called travelmate and then reboot.
It should show up last in system or network. I have not used it in quite a while.

I looked up the support thread for you.

This is the recommended build for your pi3
https://firmware-selector.openwrt.org/?version=22.03.5&target=bcm27xx%2Fbcm2710&id=rpi-3

I used this to get a good build on the Pi4b but I chose your pi; choose builds. It is going to add a lot of features.

I recommend this because I do not like CLI either and I can add the drivers for the wifi card I use for the wan just by adding it to the script.

Depending on server traffic it can be 2 minutes to add the packages or hours. If it says it is building leave it alone it will, eventually, finish.

I should add I do not need travelmate because my VPN, hotspot shield, loads on the device. But it will tunnel.
https://firmware-selector.openwrt.org/?version=22.03.5&target=bcm27xx%2Fbcm2710&id=rpi-3

I'm presuming you know how to disable the config for your home, search for APs and add them.