A few GC environment variables have no runtimeconfig.json equivalent.
This proposal is to add new runtimeconfig.json settings with the same effect as existing environment variables.
Proposed new settings:

• "System.GC.CpuGroup": Same as COMPlus_GCCpuGroup
• "System.GC.HighMemoryPercent": Same as COMPlus_GCHighMemPercent
• "System.GC.LargePages": Same as COMPlus_GCLargePages
• "System.GC.HeapAffinitizeRanges": Same as COMPlus_GCHeapAffinitizeRanges