Does this really give 20% better GPU performance?

I seen this suggested in a post months ago and was wondering has anyone actually tried and tested it?

"In the BIOS.

Hook up a keyboard, turn on power, smash DEL a bunch till the BIOS pops up, hit right ctrl + right shift + left alt + F2 to enable developer menus.

In "Advanced -> CPU Configuration" menu enable Flex Ratio, set it to 4

In "Advanced -> Power & Performance" menu, disable overclocking lock

Go to "Advanced -> Power & Performance -> CPU - Power Management Control -> CPU Lock Config" submenu, disable CFG Lock

Save and exit, smash DEL again to get back into BIOS

go to "Advanced -> Power & Performance -> CPU - Power Management Control -> View/Configure Turbo Options -> Turbo Ratio Limit Options"

set "P-Core Turbo Ratio Limit Ratio0-7 (TRLR)" to 25
set "E-Core Turbo Ratio Limit Ratio0-7" to 20

save and exit

You could get fancy and figure out a curve that allows better GPU boost while still allowing CPU to turbo higher in low load. Something like 48, 43, 38, 33, 28, 23, 23, 23 for P-Cores and 38, 33, 28, 23, 18, 18, 18,18 for E-Cores on the 155H. For the 135H you would have 2 fewer P-Core slots so it would be something like 46, 38, 30, 22, 22, 22, 22, 22. This assumes you want your core speeds limited to 2300/1800 for P and E cores under full load."