OpenVPN Site to Site - Failover on client site

[unclesam87]

hello,
i have two opnsense on different sites, both connected through an openvpn.
this works like a charm, especially on the server site, as we have a stable fiber connection. but on the client site is a sometimes broken but usually better vdsl connection, as a failover we have a cable solution.
sadly, i don't find a good solution to do a real failover on the client site - i am thankful for every tipp or trick that brings me to an stable solution.
(as an setup i used the official documentation of opnsense for site to site)

thxxx