I never doubted you, @DannyP! And I do think many Speedster and Spyder owners can build and run engines to higher static CRs than was common 20 years ago in VW engine world.
Aside from better spark control, and better heads, it's just true that these cars are usually a bit lighter than a Beetle sedan and—most crucial—their drivers are less likely than the average person to lug the car up a ski jump in third gear with nine frat boys piled on it to "set the record."
That said, I think you—the Weber Whisperer with the fastidious tuning habits—are about the ideal candidate for a 10+ CR Type 1 and, were I an engine builder, I would consider you a different sort of customer than say, Lane Anderson or myself.
Not necessarily "better," just "different."
And yet here we are, in a world where literally any junkyard Subaru mill you can find comes with a static CR at 10 or above.
That's the difference, isn't it? To run 10-1 CR with 1930s tech, you need to know something about engines and act on that knowledge. With 2000s tech it's just standard equipment; adjust the valves at 100,000 miles.