That won't stop people from making "safe" moves. Granted, in some situations when a number other than 0 is shown and there are some unknown neighbours, it's better to guess than to shoot. But since the there's an advantage to guess before your opponent guesses when a number other than 0 is shown, it's better to shoot somewhere knowing where it will reveal a 0 than to shoot somewhere where it may reveal a number other than 0.

But with this proposed variation, it's even more important that squares you've guessed are marked in someway, and we haven't seen guessed squares marked in regular Frog Legs/Finder yet.