mIRC should add a per-connection static identifier named $servergroup that preserves knowledge of the server group that was connected to. This would eliminate need for $server($server).group which is the current wisdom and ineffective as shown above.
If so inclined, let's go full steam.
$server (already exists. returns the server connected address)
$serverip (already exists. returns server connected IP address)
$port (already exists. returns server connected port)
$servertarget (already exists. returns server intended address)
$servertargetports (new: returns full list of intended target ports)
$servergroup (new: similar to $server($server).group)
$serverpass (new: similar to $server($server).pass or /server [pass])
$servermethod (new: similar to $server($server).method or /server -l [method])
$servermethodpass (new: similar to $server($server).methodpass | needs /server -l [methodpass])
$serverdesc (new: similar to $server($server).desc)
I don't know what STARTTLS is, but there are no identifiers for this. /server -t
I don't know what bypass STS is, but there are no identifiers for this. /server -u
I don't think there are any identifiers for IPv4 or IPv6 identified connection, but /server -4 and -6 exist.
Other related identifiers are $ssl, $status, $network