Almost exclusively applied from measure 51 down:

Since the drums are more prominent, if there was any negligible difference between the primary snare hits and the keyboard, the drums would take sync priority. If disparities were deemed to have exceeded what would be considered negligible, then drum syncing is dropped entirely, leaving tempo changes only for the guitar/keyboard. 

Measure 51 down:

Steps felt too sparse here with the drums omitted, so the only solution (since they rarely layered perfectly) was to constantly switch back and forth, slowly segueing out of the drums as the keyboard solo began to culminate and the drums would begin to interfere. By measure 69 the drums were entirely phased out. 
