Variable substitution in UserKnownHostsFile configuration option

[Dmitry Katsubo]

Dear OpenSSH developers,

Do you find it a good idea if variable substitution is implemented in
UserKnownHostsFile the same way it is done for IdentityFile? In
ssh_config I would like to write something like

UserKnownHostsFile ~/keys/%r/known_hosts

Thanks!

-- 
With best regards,
Dmitry