Thermoquad low vacuum readings

Here are a couple of plugs. With an otoscope I see I have a medium gray band halfway up the porcelain. (I believe the bottom of the porcelain is mostly WOT?)

With the Eddy 750 I could barely get any color at the very bottom no matter how big I jetted the secondaries.

Edit: The plugs are from running 91 octane "real gasoline"...