if everyone can play the card on a super bonus, it is not a advantage over other players
Not everyone does.
Step 1. Have a map with a huge 0 superbonus, maybe even the whole map. Since it's 0, the bonus box won't show up on the map.
Step 2. Play a card on the bonus, that most players won't spot.
Step 3. Have full intel.
The 'fix' is to just use recon and not suv. card. But on some bigger maps, a recon is too small. I remember wanting someting similar way back in the WarLight days. But anyway, point is a mod that skips recon cards on bonuses with more then ~15 terr is easy to make.