Search notes:

Registry: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock

AllowAllTrustedApps

Setting this value to 1 (DWORD) enables sideloading.

AllowDevelopmentWithoutDevLicense

Setting this value to 1 (DWORD) enables developer mode: 
reg add HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock /t REG_DWORD /f /v AllowDevelopmentWithoutDevLicense /d 1
Github repository about-Windows-Registry, path: /HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/Windows/CurrentVersion/AppModelUnlock/AllowDevelopmentWithoutDevLicense.bat

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