I'm really curious to learn about how others allocate (or find time) in their schedule each day to reflect on a problem they're attempting to solve (personal or professional).
My personal anecdote:
I find that I tend to solve "hard" problems during periods of unconscious processing (times where I'm NOT actively thinking about the problem). However, I also know I need to spend a lot of active time thinking about the problem first, before my brain can "take over". I'm usually able to structure in the unconscious processing time with things like exercise, in particular long distance hiking (5+ hours ideally) on weekends.
Finding time to reflect on problems in the middle of the week, in an active sense, has been my hardest challenge. As someone who codes all day for my startup, I can easily get into a groove for 10+ hours and not take any meaningful reflection breaks.
If something is really complex / important / hard to change later, then I'll usually stop after the research phase and allow my unconscious mind to chew away on the solution, most commonly for me the 'Aha moment' comes during my morning workout. When I'm really stuck I re-read all my collected material, search for prior art again and repeat the process. Sometimes time forces me to just start building, although those are the times when I typically end up refactoring later.
I definitely agree that time away from the problem to reflect leads to a better solution, but IMHO you have to have a really great problem statement and good context for the subconscious to do its best work.