Be careful of calling this an ideal employee.
I, for example, tend to have a little bit of such a schedule, but what I work on at home is so much more exciting, making the job much more frustrating in comparison. Also, one is typically not allowed (or it is not possible) to apply all the really good ideas that one tested/implemented for the home projects at work.
Thus, the kind of employees who apply such a pattern are often very, very passionate about programming - but this kind of passion often makes them
- more frustrated at work (i.e. they might be cynical),
- less subservient (they often know better - from their "night work" - that a requirement makes no sense, and may be vocal about it),
- very opinionated about their "technological taste", not necessarily fitting the technological taste that the employer would love to see in the work (they have seen a lot more programming techniques).
The next step is keeping the homelab at arm's length from stuff you actually depend on. My pfsense router Just Works with tons of cool stuff on it but if I get the itch to push it a bit further... walk away and make a VM in the shed!
But the skill and experience stick with you for lifetime.
You have all the time in the world, what you don't have is priorities.
I have a prioritised list, it's simply that not everything fits inside the list, because my time is limited.
Instead of "Not enough time" we could say "This is not high enough a priority".