UAL,
Yes it is parallel towards the rear of the canopy surface. That is the reference point I used to set the incidence on mine and it was right on the money. It slopes downward very slightly as you get out towards the front of the canopy, but if you set the digital level so that the back edge of the level is just barely lapped over the forward edge of the rudder servo mounting plate you will be right on it.

If you level the canopy surface, you can set the stabs at zero and the wings at +.5.
I flew mine a few days ago and all it needed was 2 clicks of down elevator for level flight. Down lines appeared to be pretty doggone straight as well.

My stab adjusters are bottomed out though, I wanted to take the down elevator out by slightly increasing the positive incidence of the stabs but since I have no room for adjustment Im just going to reduce the positive incidence in the wing slightly and see if that does it.