You`ll never believe what Dean said to me after I told him that my last roll of film was the best ever using the iPhone app.
He said you don`t need any service and just use the phone app, it`s much more reliable and technologically advanced than
the phonemic meter.
Dean said also the results on film is more forgiving than with slide film. Film will tend to have better results with less critical exposure.
Slide film would show much more of a shutter problem than film...!
but does that solve your problem with the meterhead? I'm sure Dean doesn't need to solicit additional work either.