When you create a new user profile, you have 3 options:
- Enable app installs and updates (from any source)
- Enable app installs and updates from first party sources only
- Disable app installs and updates
For guest mode however, you can only select from the last 2 options. The ability to download apps from the first option from any source is not there. Not grayed out but entirely missing. I get that if you give your phone to an actual guest you want to select the last 2 options only, but that's why the user choice of selecting which one should and currently does exist in the first place. Make it harder to select the first option, have a confirm dialogue if the first is selected, have it in red, have exclamation points and add words to it, have it all the way at the bottom of the screen away from the first 2 options, just do anything but remove it please.
For those of us who use Guest Mode as a way to have all data wiped on auto reboot, it is a serious privacy issue and thus eventual physical security issue to have every app you plan on using in Guest mode needing to be pre-installed in Owner profile. Some apps to not arise dangerous attention need to be installed in Guest Mode only and not have its install revealed in Owner Profile. GrapheneOS has considered adding a pre boot password to prevent app installs from being known to forensics. The least GrapheneOS could do is let the most sensitive apps where some countries will punish you for just having certain apps installed be installed from within Guest Mode directly instead of alerting attention by forcing having its install in Owner Profile first.