Thank you, this is a super helpful post!  I have decided to replicate what your previous employer was doing by entering expenses as a net $0 bill under the vendor who was paid that shows expenses as a + amount on one line (billing to proper expense acct) offset by a second line showing the same amt as a - amount (billing to the payroll liability account).  Then in the payroll module, I point the payroll reimbursement item to this same payroll liability account.