Pitcher throwing to unoccupied base

[BSBAL18]

So if R1 breaks for second early after the pitcher comes set, these threads are saying that the legal spin-move for a RHP that would happen for a normal pickoff attempt at 2nd, is legal, because he is making a play on an advancing runner, even though there is no runner. The pitcher is *not* required to stepoff before throwing to second because of the "making a play on an advancing runer".

I wonder why RHP pitchers dont use a coach in the dugout to show a runner stealing while the pitcher makes a slower leg-lift to throw home, just to see a visual sign from dugout that the runner is stealing so the RHP would initiate his spinmove for a pickoff.