Hi. Enabling Full Mode will make internet traffic for the connected client go through your VPN, which is not necessary if your goal is to access cameras.
That would be a problem. It sounds like you won't be able to accept incoming connections using IPv4.
If the ISPs at both ends of the VPN connection support IPv6, you may be able to connect the VPN client to the router's IPv6 address. But it is unclear if TP-Link Omada's OpenVPN server is listening on IPv6.
Here's a reddit post where someone was unable to make it work. In his case it could have been a firewall issue. I assume his router was automatically creating an IPv4 firewall rule to allow the incoming VPN traffic, but probably neglected to do the same for IPv6. (IPv6 is typically well supported on the backend of routers, but overlooked in their GUI features). It is possible that one would need to manually create a rule in the router's IPv6 firewall to allow the VPN traffic to the router's IPv6 address.