An artist at The Witness is working at a personal project at a similar rythm. He has written a blog post about it, where he does talk about some of the issues you mention:
http://twelveminutesgame.com/2014/12/one-hour-a-day-every-single-day/
I do believe this approach has some advantages (if time constraints are not an issue), but as he mentions in the blog post there is a huge difference to Casey´s approach, which is being able to work on it for a few hours straight occasionally (of course not having to stop right at the one hour mark and not having to explain himself to an audience as he is working are also huge differences... but I guess you know what I meant).
I do wonder if some of those issues that are solved when spacing his keyboard time apart are due more to his inexperience as a programmer (I can't tell how experienced he is at programming from the blog).