Oops, I've seen the referenced issue that tries to solve the problem just now. 😁
I can confirm that the setting Hide "Discard changes" and "Revert to defaults" button on the page /admin/config/gin_lb/settings doesn't work at the moment.
It's supposed to be enabled by default, if I understand correctly. It's always disabled, though.
If I enable the setting and save the form, this setting appears as disabled again. Even if it's disabled, the buttons do not appear in the Layout Builder.
The Discard changes button and the Revert to defaults button do entirely different things and should be treated independently. Therefore, there should be a separate setting for each button.
The possibility to discard changes that may have gone wrong is crucial for every editor.
The possibility to reset the entire page back to defaults, on the other hand, is super dangerous and I always hide it to prevent accidents.