I haven't extensively tested it but in a very quick test I had it running at 2100MHz/8500MHz fine with only a slight voltage bump.
Sometimes it drops back a bit due to vrel or power to around 2020 ish and nothing I can do about that even with 112% PT.
Needs the extra voltage to get 2100MHz stable - tried on stock voltage just now and it crashed hard 20 seconds into heaven benchmark.