I think something Ive learned from trying to fly very slow is what looks like a tip stall is more often a loss of yaw stability. I think my planes tails are "stalling" before the wings. So I am trying to correct roll at low speed with throttle and rudder instead of bashing the aileron stick.
I would like to see more pictures of your wing and its slats/slots.
The wing on this project or some of my other stuff?
In fact, I have one you can chug along doing high alpha, hover in the wind, and handle gusty winds with ease. (have video)
Try this exercise.
Take the plane up 4 crash heights.
Throttle back and level, add elevator and aileron(no rudder) into a high alpha mode. Keep flaring slowly, plane will roll over and dive one way or other.
Go back up to same altitude after recovery and do it again. Plane in most cases will roll over same way.
Now climb up again, do the same except now as you slow down in high alpha, add opposite rudder to counteract roll, and slow it down(add more rudder) until it it rolls over and drops out.
Now game on, do it until it now is comfortable and keep it a tic away from stalling.
If I use ailerons enough, plane rolls over to move right. Imagine adding too much aileron while doing a flare or high alpha near stall.
I use rudder, elevator, throttle management and a small amount of aileron to move from one side to the other. If I used a lot of aileron, wouldn't the plane roll over? So it becomes the rudder that allows it to move side to side.
My imaginary cube is 20x20x20ft to fly in. Run the speed of the video at .25 and watch the rudder, elevator, throttle change and see how little the aileron is used. After awhile, you will sense(feel) when you are near rollover.