[Infamous]

You can't just remove the ammunation enter/exit icons. You have to remove all the default ones if your going to go down that road.

Ref: https://sampwiki.blast.hk/wiki/DisableInteriorEnterExits

Edit: An alternative would be to check the interior they are in when the armour is applied. Not 100% effective but it would catch most cheaters that apply it as soon as they spawn.