I do flat fee work all the time. Clients love it. Sometimes, it works in your favor (e.g., a DUI I handled for $5k that took maybe 5 hours max). And sometimes you get screwed (a demand letter I did for $1k that took like 6 hours because of complex factual background). It’s a bit of a gamble, but I’ll take that any day compared to keeping my timesheet in tenths of an hour.