"My problem is wet logs and wet river rocks. The river rocks are smoother than the granite rocks on portages in Quetico and exposed to high water that starts moss growing."

The standard fly-fishing answer to moss and other slick surfaces is felt soles.

There's a version of of the Chota QT - the Brookie, I think it is - that has both rubber and a felt patch under the forefoot.  Check any fly fishing store that carries Chota stuff.

There are a few other wading boots with a combo sole also.