I have had most of the Morris profile planes and all did the maneuvers well including climbing flat spins

. I think you are missing that there is just something too stable about this Extra. I have never had a fun-fly plane I couldn't flat spin before. This one is weird[X(]. Just to stable.
ORIGINAL: Razor-RCU
I guess I missed the question...

You want to stall the airplane? Have you tried a Profile? It will fly better than both of these without mods.