A class op applied to a dictionary doesn't do much work, so it's not
a great idea to float it out (except possibly to the top level.

See Note [Floating over-saturated applications] in SetLevels

I also renamed "floatOutPartialApplications" to "floatOutOverSatApps";
the former is deeply confusing, since there is no partial application
involved -- quite the reverse, it is *over* saturated.