Thanks zephyr911, couponvan & mval (all would be outstanding superhero names, by the way) for the acceptance!
I have had deep thoughts (not by Jack Handy) and the part time work idea is appealing for many reasons:
#1 Obviously, there is the extra income, and earlier "full time retirement".
#2 This is a second career for me, only about 3 years in, I still kind of enjoy it and haven't burnt out quite yet (although by 2022...)
#3 In my field, I'm lucky enough to find employment almost anywhere in the US (unless there are major systemic changes) and work the hours I prefer. I could work full time 3 mos and take 9 off, or maybe just work 1 day a week, so decent flexibility. Plus with a boatload of F U money to say "goodbye" if the work no longer suits me adds even more.
#4 Work has always been a social outlet for me. Not necessarily when working, but a good place to find folks with similar interests to hang with outside of work. Cutting this off cold turkey may have negative consequences.
#5 I avoid obsolescence in my field, staying up to date and employable in the future. If the doomsayers are right for once and our investment returns suck, it's an added safety margin of jumping back into full time work for a year or two if need be.
#6 It avoids the identity crisis many people on the forum have expressed when dealing with family & friends who don't get FIRE. "What your retired at 46?!?! Thats impossible, you're just lazy!". Nope, still employed here...cough 300 hours a year, cough...
#7 It will make me feel useful during the inevitable periods of time in the future when i ponder the meaning of my existence (yes, my 40's may bring about a mid life crisis).
Frankly, Im surprised there isn't more discussion about people specifically planning "almost FI" on the forum. Since the likelihood is so high a 30 or 40 something retiree will make money again at some point anyway. It almost seems overkill to be 100 percent FI with a 4 percent or less withdrawal rate before cutting back a bit and let loose. At the very least, slowly reducing work hours probably makes for an easier transition. Curious about others thoughts on this.