The allowlist is an update that blocks the majority of FastFlags. According to Roblox its for security and overrall stability. And another reasoning is surprisingly child safety.
This update was noted on the 29th of september in 2025
The Fast Flag Allowlist is a new system that limits which Fast Flags you can configure locally in your ClientAppSettings.json file. The allowlist is subject to change, and Roblox reserves the right to add or remove flags based on platform needs and community feedback at any time.
Geometry:
- DFIntCSGLevelOfDetailSwitchingDistance
- DFIntCSGLevelOfDetailSwitchingDistanceL12
- DFIntCSGLevelOfDetailSwitchingDistanceL23
- DFIntCSGLevelOfDetailSwitchingDistanceL34
Rendering:
- FFlagHandleAltEnterFullscreenManually
- DFFlagTextureQualityOverrideEnabled
- DFIntTextureQualityOverride
- FIntDebugForceMSAASamples
- DFFlagDisableDPIScale
- FFlagDebugGraphicsPreferD3D11
- FFlagDebugSkyGray
- DFFlagDebugPauseVoxelizer
- DFIntDebugFRMQualityLevelOverride
- FIntFRMMaxGrassDistance
- FIntFRMMinGrassDistance
- FFlagDebugGraphicsPreferVulkan
- FFlagDebugGraphicsPreferOpenGL
User Interface:
- FIntGrassMovementReducedMotionFactor
But Roblox Studio will remain to have FastFlags. To request a new FastFlags in the allowlist you will have to convince Roblox in a feature submit.
https://www.roblox.com/games/16627479038/Bloxstrap-Testing-Area