Most planes have wash out built in. Remember wash out raises the stall speed only a little. The way it works is any wing in which the wing stalls at the tip first will usually stall with a nasty snap. If you put wash out in the wing tips if one tip begins to stall the wash out "WARP" will cause the still flying wing to go down and help make the stall less violent, But a quad tapered wing will always stall tip first. That is why we progress to "advanced" planes when we want to challenge our skills.
One of the snappiest plane I have ever flown was the Kyosho 40 size Cap 21.....not only did it have a nasty stall it also gave almost zero warning before it stalled. One minute you were flying the next minute you were spinning for the ground. It sure kept me on my toes. Finally lost an engine...... tried to make the field..
.....well it is gone now. I still have one, I plan to build one day.

Anyways the key is, big thick wings that are lightly loaded have a high stall speed and visa versa.
Brian