Cinebench R23 vmin will be about 1.15v (to 1.16v) at 5.5 ghz.
1.20v at 5.6 ghz.
1.26v at 5.7 ghz, based on your P core rating. I am referring to load voltage (die sense) shown in HWinfo64.
You can also see this in Asus "OCtool", you can download from robertosampiao's thread, and go to Raw VRM. Note: having Raw VRM open drops you about 600 R23 points. You get a similar drop if "Asus EC" is enabled in HWinfo64! you can disable this in hWinfo startup settings.
Anyway...
This would be about equal to 1.255v Bios set + LLC6 for 5.5 ghz,
1.30v Bios set + LLC6 for 5.6 ghz,
1.370v-1.375v Bios set + LLC6 for 5.7 ghz.
You will probably NOT be stable under these bios set voltages (load vmins listed above that) without custom loop or delid. This is based on a 420mm AIO.
Y-cruncher "SFT" and Stockfish (32 threads) will require at least 50mv higher Bios voltage set to be stable, than R23
Determining E core vmin is more difficult since you want to use x43. Since you don't want the P-cores to interfere with this, you can set the P cores to x51 (Sync all cores), and x43 e cores.
Then, start at 1.220v Bios set + LLC5 (yes, 5).
Now you want to run Y-cruncher, disable all tests (press 1, then 8), enable SFT test only (press 13) then start the test.
Your goal is to pass 15 loops without a "red" error appearing.
Any red errors will be on logical cores 16-31, which are the E-cores. It should always be on the same core every time, which is the weakest core.
If/When you get an error, raise bios voltage by 5mv (0.005v), e.g. 1.220v-1.225v) and try again.
If you manage to pass, drop the voltage by 5mv and try again, until you fail.
Once you fail, raise voltage AGAIN by 5mv and re-test to confirm. That is your e-core vmin for x43 under worst case loads.
This is helpful to know. R23 (cinebench) doesn't require as much vcore as SFT.