Yes, the cool down operation of the FR-803B can be disabled by changing the 6th parameter in the system's setup.  This parameter controls the forced cool down.  The factory default setting is zero (0) which turns the override off, forcing a cool down of the hand piece to 100 C even if the START/STOP button is pressed.

When the parameter is set to one (1) the override function is on, and the cool down air will stop when the START/STOP button is pressed if the display temperature is under 380 C.

NOTE:  When the forced cool down override is turned on, be aware that starting a profile in automatic mode will start the air flow, and if the heater has not cooled, it is possible that the hot air will be above the set tempearture for the initial stage in the profile.  As the air flow cools the heater, the timer for the first stage will start once the first stage target temperature is reached.  From that point, the profile runs normally.

IMPORTANT:  Disabling the forced cool down can cause the heat to build up in the hand piece which can shorten the life of the heating element and can cause damage to the hand piece.