Maybe place the hidden blip back so that whenever you carry or use a sniper rifle it will turn on.
If you switch to uzi or sawn off it will be switched off again.
So hidden blip would only be used with sniper rifles! ( for real sneaky sniper actions... )
Snipers with hidden blips wouldn't be such a big disadvantage for new players.
Snipers with hidden blips woudn't be such a problem at the race start, if it is made possible for admins to see the hidden blips. ( & even without hidden blip people can mess up races like that anyway.)
Hidden blip on vehicles would be more of a disadvantage to (new) players than when its used with a sniper rifle.
So if you guys return hidden blip, i would say create it the sniper way^^