A small observation..
..it seems the Mark 16 definately turns a bit worse than the other Spitfires. Planes like the 109 or P-47, 190 or etc won't outturn Spitfires no matter what variant it is so it's a less noticeable for those types of planes, but for planes that have comparable turning performances the difference is quite pronounced.
When pitted against an average level of pilot, the Ki-84 would outturn the Spit5 when both planes are low speed and with combat flaps out. In case the Ki-84 is heavy with fuel and the Spit5 is not, the results are often hard to aniticipate. It will outturn the standard Spit9 after quite many circles with no flaps, or, in 2~3 circles with flaps out.
However, against the Mark 16, the Ki-84 seems to be able to plain outturn it within one or two circles, without flaps required.
I'll probably have to retest all the new planes to update the turn testings, but I'm more or less certain about that.