On the Hex, i drove the MT2216 900kV with the 10x5 Graupners and the Wooden 11x4 Gemfans, yes i had little Yaw problems but never tried to tune them out.
But never had this divergence thing there and yes i´ve pushed em very hard.
On the X8 divergence is just a little noticable but i never lost kontroll on it.
Like Max mentioned i believe with a little more time for tuning on the X8 i could completly eliminate this for ever.
Your observations about the RCT 11x5.5 i can confirm, in fact they look identicaly to the old tiger 11x4.5 but yea, the are not that precise.
I fly on the r0sewhite Rubina the RCT 8x5.5 Tiger clones and i got them balanzed with some ornate tricks
I would also try the Tiger 8x3.8 just to compare but meanwhile i need a sponsor, thought
to summ up i would say, the more pitch, the more controll u archieve for your configuration, the less problems occur.