I use the mainsheet cleat to hold the main the majority of the time however I am constantly adjusting. Confidence in being able to uncleat is the key.
I have attach a picture of the system that came with my boat, while it has some minor dissadvantages which can be overcome with changes in procedure the advantage of being able to uncleat anytime by taking the load and easing the sheet to clear the cleat, the "flick" or a well placed kick as I skid across the tramp make it worth it.
Note how the cleat arm tracks the skipper position as you move rearwards while reaching and therefore trapeze higher as the trap wire shortens.
Darryn