tun interface and netmask

Hi All,

Problem I want to solve:
I would like the tun interface to 'support' more than one host. Right now, when
I setup a tun interface, it's only activated on the dest IP, regardless of the
netmask used.

my /etc/hostname.tun0:
inet 192.168.40.10 255.255.255.0 192.168.40.1

A workaround I've done, is adding a route:
route add -inet 192.168.40.10/24 192.168.40.10

More info:
Wireguard is using tun0 on machine A; I would like machine B and machine C to
also access machine A, all on machine A's tun0 interface - without the need for
additional tun interfaces.

Fortunately the route trick above works.

Question:
Is the route add the legitimate way to do this? Can tun support more than one
host, or is truly point-to-point?

Thanks!