PastorBob:
Would suggest to keep using those Scott Matthauser pads. By far rhe best we've ever used.
Ours lasted for 64,000 miles with only the rear ones showing lotsa wear but still functioning 100%.
Using Tektro Mini V-brake in rear with KoolStop pads and Shimano calipher up front with Shinmano pads on our Zona tandem. Replaced the KoolStops once in 34,000 miles; Shimanos are still original.
Your mileage may vary . . .
Pedal on!
Rudy and Kay/zonatandem