Weird or maddening "mechanics"

[Tru_in_Blu]

I always use a verbal "no catch" on a trapped ball with a safe signal.

Especially with runners on base, I think I should make a call as soon as I can so as not to put anyone in jeopardy.

I've had partners not say or do anything and runners are hung out to dry - not knowing whether to go back to their base or attempt to get to the next base.

So what's a better protocol/mechanic for a line drive that F4 traps on the backhand. A runner on first and the BU might not be able to tell.