When I chose "Customize Routing Rules", I'm able to run both VPN clients at the same time by following the directions from Multiple VPN Client. The lower metric value is used for Wiregurad route so it would have higher priority for the home network (192.168.10.x). Everything else needs to pass through OpenVPN (default route).
I used tracert command from my laptop and confirmed both VPN paths are working (when "Block non-VPN traffic" not enabled):
When "Block non-VPN traffic" is enabled, my PC can't resolve any domain name but no issue is observed on the router (ssh). The results of running nslookup command on the router (ssh) and my laptop are:
