The setting for the site-to-site I've suggested above is necessary anyway for correct routing.
Look, if you try to access a LAN device on site B from a VPN client on site A, the packet is sent to the site A pfSense, cause of the route which is pushed to the client. Site A directs the packet to site B, cause it also has a route for the site Bs LAN. The packet reach the device on site B, which send its response addressed to an IP in 10.10.210.0/24 back to its default gateway which is site B pfSense. If there is no special route for 10.10.210.0/24 the gateway will send the packet to its upstream gateway, thus to the internet where the packet will be dropped, cause the destination subnet is not routed there.
Therefor you need a route on site B which direct packets destined to 10.10.210.0/24 back over site-to-site tunnel to site A.