I've found that with my stable curve i get better results running +25 MHz than something like 75 or even 100 MHz as boost clock, still have to test it the voltage offset of 0.0375 could help me handle a better curve since this has been tested with no offset and best core seems not able to be 100% under -5Very likely some of your cores are not stable.
Use CoreCycler to verify, -25 all core is extreme.
High LLC and PWM are required to sustain low CO counts.
You can also set Boost clock from 0 to 50 to reduce the frequency boost, performances will be slightly impacted.
Unless you have a royal cooling the cores will not keep more than 5100 MHz on sustained load.