The server controls the pace of the Game
I often hear Our distinguished and sometimes dribbly dick commentators stating how the server controls the pace of Their service game. I gather there is a time limit on this,but We often see a well known Player Whose name I won't mention(Masha) controlling the Opponents serving pace as well.
This when not too blatantly carried out can really unnerve an Opponent with a short fuse,and is a very good tactic. Masha is not the only expert at this, the delightful Miss Oops Mrs, Dechy did a very good job a few weeks back, just throwing Her Opponent off Their stride.
The point of this rambling is have any or if not, why haven't any servers being treated in this manner just let strip with Their serve when They estimate the time is up?
Umpires never seem to act on this, should there be a buzzer, or at least the odd warning?