@jackals 

RE: I'm having to create a spurious payroll to make sure the amounts end up in COGS, even though that's not the basis for charging the client nor for paying the members. 

I really don't think you should do this, unless I misunderstand something.  The time is not GOGS if  you don't have any actual Costs associated with it.

The resulting costs wills appear on your P&L, but they're not real.  I suppose you could work around this by offsetting the COGS account you use on the paychecks (also weird) with a Journal, perhaps to an Equity account.  This would neutralize the GOGS/expense and alter the Equity account to reflect the work the owners have put into the business, which kind of makes sense.

I still don't understand why you (or anyone) would want to do this?  To me, time is not an expense just like mileage is not an expense.  (The costs of running the company car are an expense, and they are reflected in fuel, maintenance, depreciation, and so on.)