SetupVar for Windows supports reading and writing the following NVRAM variables now:
| Variable | GUID | Command |
|---|---|---|
| Setup | EC87D643-EBA4-4BB5-A1E5-00003F3E3FBB | -AmiSetup |
| Setup | A04A27F4-DF00-4D42-B552-39511302113D | -InsydeSetup |
| PchSetup | 4570B7F1-ADE8-4943-8DC3-406472842384 | -PchSetup |
| SaSetup | 72C5E28C-7783-43A1-8767-FAD73FCCAFA4 | -SaSetup |
| CpuSetup | B08F97FF-E6E8-4193-A997-5E9E9B0ADB32 | -CpuSetup |
| IntelSetup | EC87D643-EBA4-4BB5-A1E5-3F3E36B20DA9 | -IntelSetup |
| SystemConfig | A04A27F4-DF00-4D42-B552-39511302113D | -SystemConfig |
| KEK | 8BE4DF61-93CA-11D2-AA0D-00E098032B8C | -AmiKek |
| PK | 8BE4DF61-93CA-11D2-AA0D-00E098032B8C | -AmiPk |
I have tested the -AmiSetup, -AmiKek, and -AmiPk commands on my AMI motherboard.
Additionally, SetupVar can now display the data of NVRAM variables:
If you would like me to add more variables or features, please let me know! 
Credit to @Sweet_Kitten for helping me with some of the variables.