FusionHub NAT and site-to-site VPN

Thank you @MartinLangmaid,
As stated, Site 1 has several public IPs.
Site 2 has public IP.

I see that comment from 2015, isn’t it contradict with what you said regarding connecting both sites to fusionhub?

Pepvpn/fusionhub will maintain the tunnels across all the wan interfaces of Site 1? I need it to keep the connection between sites up when a failover happen between WANs interfaces.

Also, the public IPs are not static so I need to make sure the tunnels stay up when the external ip of one of the interfaces change, is it possible? do I have to use ddns to achieve it? or fusionhub/pepvpn will maintain it for me automatically?

Thanks