I have installed your plug in and am having issues with one aspect that maybe I am just missing how to properly set up.  My wife is a massage therapist (the worker) and has set up 3 products 30 min, 60 min and 90 minute sessions and set a start and end time for all three products as 9-2.  What I see happening is someone will book a 30 minute at 9, which takes them to 9:30 but the 60 min treatments don't adjust to allow a 9:30 slot.  all the other products keep the same appointment times.  This ends up with chunks of unusable time.  Is there a setting i'm missing to fix this?  Thank you