It works. You guys are pretty smart.
An adjust to the % (click on > next to schedule name, click on duration hour/min amount, adjust durations from 100 to max 150%, play around until you figure out how to save (frustrating - still don't know how to reliably save - poor PC interface performance is #1 reason I tell the commercial guys to not buy Rachio at the moment - Rachio's not ready for them.)
Indeed, watering amount gets increased without anything else changing. What's happening is this % screen is separate from all ET algorithms - if the 'auto' ET calculations say 'put down 30 minutes,' then this screen allows you to put down up to 45 min with the ET auto system thinking it only got 30 min.
Indeed, this is the 'knob' to increase watering amount without changing anything else, using 'auto' mode.