Been having a play with this with my 5900x and it seems like it can get really good results, although I've not done full stability testing yet.
I went through the instructions and had these as my P1 and P2 with the Hybrid OC
P1:
CCX1 (158): 4425 MHz, 1181 mV OC=
CCX2 (133): 4325 MHz, 1181 mV OC=
P2:
CCX1 (158): 4550 MHz, 1288 mV OC=
CCX2 (133): 4500 MHz, 1288 mV OC=
And then I thought I'd do some runs with Cinebench R23 and compare with Stock and with PBO and these are the results, all readings HWInfo64, voltages are from CPU Core VID (Effective).
Stock:
Score: 20205
Voltage: 1.181v
Clock: 3.975ghz both CCX
Temp: 70.6c
Power: 130w
PBO:
Score: 21606
Voltage: 1.325v
Clock: 4.3ghz both CCX
Temp: 87c
Power: 180w
CTR:
Score: 22398
Voltage 1.181v
Clock: CCX1 - 4.425ghz, CCX2 4.325ghz
Temp - 74c
Power - 140w
So a decent amount better than PBO with stock power limits, 400mhz jump over stock with the same voltages.
My thoughts as well are that if PBO will happly run 1.325v at full load, then I could use that voltage in CTR and get even better results. However I'm a bit reluctant to push it that high, as it doesn't use FIT so could put too much voltage through and cause degradation.