I just tried something the other day. I had my wife give me a haircut without removing my piece. I just bunched up the system hair and held it top my head while she used scissors to trim my real hair. Totally amazed how good it came out. She just worked her way around the sides and back of my head. 15 minutes and I was out the door.
Just felt like being lazy and not unattach and bring out the flowbee. Sometimes you realize you need haircut as the real hair begins to look longer than the system hair.