With the advent of the FFlag allowlist, one of the most useful FFlags will soon be killed.
DFIntCanHideGuiGroupId was mostly popularized by Bloxstrap to my knowledge, and it permits the use of the built-in GUI hiding utilities that staff(?) have access to for.. anyone in the set group! These tools not only include hiding a game developer’s custom GUIs, but also the Roblox CoreGui.
These are useful for content creators trying to record footage, but also to developers themselves to take clean video of game worlds running in the client. Whilst these can be done in Studio, there is the high possibility that a bunch of debugging tools or Studio-specific behavior (i.e. RunService:IsStudio() gated code) gets ran, which may alter the experience.
I’m unsure if these should be available to anyone, but I believe the feature should be enabled for developers of games (including CoreGui hiding, that is personally my most used one for taking nice cinematic screenshots and recording trailers at full resolution, rather than needing to crop in video to hide CoreGui elements), similarly to how freecam is available to developers.
Whilst this functionality can be written by a developer themselves in games, it is impossible to hide the CoreGui this way, and it seems a bit pointless writing a feature that already exists in the engine.