the fix -- more thrust - not just the prop - more power .
typically - this type craft is "stalled" during much of the takeoff run (run?)
Old approaches -- add a long tailwheel setup which places th model at about 8-10 degrees aoa .
this lets you get into takeoff speed earlier as the combind drag is lessened.
- keep it on the ground till it is skimming --then gently lift off.
anotherhepl- move main gear aft to apoint that the model is actually "tippy" on the gear -
this lets the drag on the gear move aft and decreases the steering effect it can produce.
really nice looking model -
all of the fussing with wing AOA is wasted time - set both panels equally .
I would guess-from looking at the pic - that the wing loading is on the high side - which means that LOTS of takeoff speed is required to take off at a lower AOA.
If you lift off early - the tail group is simply blanked out and yaw control is reduced to nothing.
don't give up -