just as a sample of the controls you wanted I did this
Code:
using a group to just get the checkmark
menu status,channel,query {
  Away System Sample
  .  $style($iif($group(#away.on) == off,0,1)) Away System On : { .disable #away.* | .enable #away.on | set %awaytime $ctime | echo -a Away 3ON }
  .  $style($iif($group(#away.off) == off,0,1)) Away System Off : { .disable #away.* | .enable #away.off | awaytime }
}
#away.on off
#away.on end
#away.off on
alias awaytime {
  echo -a $me was away:12 $duration($calc($ctime - %awaytime))
  unset %awaytime
}
#away.off end