I think letting devs 2 hours a day, that they can flex so if they wanna use it on Fridays its fine, for personal projects, whether internal or otherwise. Just think of all the random tech debt that could be resolved if devs had 2 hours a day to code anything, including new projects that benefit everyone. Most people can only squeeze out about 6 hours worth of real work anyway. You burn up by the end of the day.