pfSense

No bug there.

You don't use quotes with a route statement. You might be thinking of a push route but then the "route" part is also inside the quotes, as the whole route statement is an argument to push, the parameters to route are not quoted as a whole.

You don't even need to use route statements, use the "Remote Networks" controls for that and let the GUI sort it out.

The gateway is determined by OpenVPN internally, and depending on your setup it may be an address that isn't really "there" but it's set so that the OS will put the traffic on the interface, nothing more. OpenVPN handles the rest.