Don't get me started on flowbench BS. My SF-1020 has atmospheric condition data and corrections it has NEVER read higher than anyone else's advertised flow numbers. You are right about flow numbers meaning actually very little. Your tricky dude with weak springs sounds like he's in the wrong trade if he thinks he's fooling anyone, and leaving a spark plug out is a dead giveaway with a +30cfm advantage showing..
That being said I purchased the heads for the 2015 EMC and saw andvantage within the rules that year. My mistake was letting Hughes sell me his CNC port "work" . I was after the pushrod pinchless aspect and know how CSA and flow work to know. J.Rob