In terms of expecting our players to look for a sign after every pitch, I'm a beast. I hammer on them to look. Not just early in the season. Throughout the season.
But in terms of expecting our players to "see" the sign, I assume that 1/2 of our players are below average at seeing the signs.
We have more signs than most teams, and we use them more than most teams, so our signs are dirt simple and very "see-able."
Nevertheless, on a squeeze (safety or suicide), I verbally inform R3 because there's no downside; only upside. Professional airline pilots should be trusted to select the proper control settings, yet they verify with verbal call-outs.
Regarding suicide, the past couple of years our suicide sign means, "Regardless of pitch location/type, you must bunt" instead of "Regardless of pitch location/type, you must bunt b/c there's a runner breaking towards home from third." For some batters, when they know they have to offer at the pitch, it increases their probability of putting down regular sac bunts. The other batters get the normal sac bunt sign for regular sacs.