What I do for start times in PRV is selecting per instument or range using drag-highlight-select ( left on piano keyboard or note name value with your mouse) or selection using the lasso feature. Then I can slide those notes, instruments or ranges a few ticks + or - & all different values from each other.
You can change by manually dragging or by entering the tick value amounts using menu / process / slide.
Using ranges works well for orchestration or scores by section i.e.-
WW-slide +6
Strings+12
Brass + 16
Perc slide +20
or selecting SATB ranges etc..