Catcher's signals where the whole defense can see them?

It's customary for the catcher to drop a sign for the pitcher. The pitcher nods his head and agrees or disagrees. But, quite frankly, no one else is expected to see the signs with this system.

If the shortstop or the 2B can see the signal then that would make 3 position players that would be able to notice the pitch selection. But, should every defensive player be aware of the pitch selection? Yes.

Now, the delicate part of this is "tipping" the pitches too early to the offense. You certainly wouldn't want the defense moving according to the pitch prior to the pitch being thrown. But, it would be nice if the outfielders knew if an offspeed pitch or a fastball was coming. Some teams try to signal to the outfield by having the middle infielders signal with a hand behind ther back. But, again, what if the middle infielders themselves can't see the pitch selection?

Some teams use more demonstrative signals if the pitcher can't see the catcher's signs. Why not do this all the time?

If a coach can stand down at 3B and signal to his team the offensive signals then shouldn't the catcher be able to do the same thing? I know. The pitches would be easier to steal. Well, if a team is in the practice of trying to steal pitches that might be true. The defenive team would want to focus on tough signals to crack or only use this signal package with runners in scoring position. It would limit the times the system is used and prevent the other team from cracking the code. Also, it would give the defense the advantage when it truly needs the advantage- with runners in scoring position.