I realize it's not proper to reply to my own post but I think I figured it out
Using simple (made-up) numbers:
Monthly pension (before 62 yrs old): $1500
Monthly pension (after 62 yrs old): $1000
Lump Sum option: $250,000
When I tried comparing pension vs. lump sum in FIRECalc the disparity was *much* larger than I anticipated. This gap closed considerably when I set my pension at $18,000 per year (1500x12) then, seven years later I made a negative adjustment of $6000 (the difference between 1500 and 1000, times 12). I didn't realize you could input a negative "pension income".