Allowing for sear friction/resistance is easy enough because it's almost negligible in relation to the amount of energy in the mainspring (which is one key omission Otteson makes and clearly states).

Negligible? So if you have 6-8 lbs of sear resistance acting against a 25 lb spring you call a 33% loss negligible? I think not, granted a 10 lb spring will probably set off the primer sometimes, but will be inconsistent at best. . . .