I have always used (beat) to indicate a pause in dialogue
but I often think it is clunky.
It stops the readers flow.
They don't wait a second before continuing reading.
Recently I have been reading some published and filmed screenplays
and each time there was a pause it was indicated by a line of full-stops.
ie ACTOR: Yes, you can go.................. no wait!
I find this far more readable and 'in the moment' but is it frowned upon