Use remote access client as gateway to route traffic to remote network

[VirtuaWin]

Hello, and happy new year to everyone on the forum!
After searching the web and this forum, I can't seem to find a solution so I'm creating this post.

I currently have a remote access OpenVPN server set up on pfSense with seven clients. All these clients are routers/firewalls (Teltonika and DrayTek). The topology mode used is the one that puts all clients in a common subnet (currently 172.20.10.0/24).
Each client has a WAN interface and a LAN interface. The LAN interface is configured with a 192.168.X.0/24 network, and each client's LAN doesn't overlap with the others. The VPN connetion is established (obviously) from the WAN network which is connected to the Internet.

With this being said, I'm currently trying to set up pfSense to use these clients as gateways to route traffic from pfSense's local networks to the 192.168.X.0/24 networks of the remote clients.

In the beginning, this seemed quite simple to me; just assign an interface to the OpenVPN server and then create gateways that use the remote client's tunnel IP address (172.20.10.X) associated with it. Then either configure static routes, or implement policy-based routing on the firewall rules, that use these gateways to route each specific 192.168.X.0/24 network to the associated client router.
As it turns out, I was wrong... At least currently, with this configuration, I cannot seem to use the remote clients as gateways to route traffic from pfSense to the remote LANs. So my question at this point is: Is this even possible or am I missing some configuration step?

Thanks.