Trying to enable an option not in menu - unclear on modding vs direct UEFI tweak?

I made a BIOS mod request over in ROG STRIX B550-I GAMING - Enable x8x4x4 bifurcation possible?

However, I’m trying to understand how to do this myself. In the relevant section I see:

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0x6124                  Suppress If: {0A 82}
0x6126 Variable 0x2 equals value in list (0x1, 0x3, 0x4, 0x6) {14 8E 02 00 04 00 01 00 03 00 04 00 06 00}
0x6134 Not {17 02}
0x6136 End {29 02}
0x6138 Setting: PCIe/GFX Lanes Configuration, Variable: 0x11 {05 91 09 00 0A 00 08 00 01 00 11 00 10 10 00 03 00}
0x6149 Option: x16, Value: 0x0 (default) {09 07 0B 00 10 00 00}
0x6150 Option: x8x8, Value: 0x1 {09 07 0C 00 00 00 01}
0x6157 Option: x8x4x4, Value: 0x2 {09 07 0D 00 00 00 02}
0x615E Option: x4x4x4x4, Value: 0x3 {09 07 0E 00 00 00 03}
0x6165 End of Options {29 02}
0x6167 End If {29 02}
0x6169 Suppress If: {0A 82}
0x616B Variable 0x2 equals value in list (0x5) {14 88 02 00 01 00 05 00}
0x6173 Not {17 02}
0x6175 End {29 02}
0x6177 Setting: PCIe/GFX Lanes Configuration, Variable: 0x11 {05 91 09 00 0A 00 09 00 01 00 11 00 10 10 00 02 00}
0x6188 Option: x16, Value: 0x0 (default) {09 07 0B 00 10 00 00}
0x618F Option: x8x8, Value: 0x1 {09 07 0C 00 00 00 01}
0x6196 Option: x8x4x4, Value: 0x2 {09 07 0D 00 00 00 02}
0x619D End of Options {29 02}
0x619F End If {29 02}
 


Does this mean it's as simple as this?

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setup_var 0x11 0x2
 


I'm also unclear how I can just make this option visible again in the BIOS - or even if it's possible on an ASUS Strix b550 I due to BIOS locking/signing.

Any help here gratefully received!

Eventually I was able to run with this EFI Shell: https://github.com/tahmid-H/Asus-ROG-B55…e/main/EFI/BOOT

And then I could do:

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setup_var AMD_PBS_SETUP 0x11 0x2
 
 


Unfortunately, it doesn't actually appear to work however.