Yes, though the last time was about 10 or 12 years ago. I recall lots of what I'll call ravines on trails down to some of the lakes off the ridge trail which added a lot of gain and loss, as would ascending/descenting to the shore. But the the Greenstone itself I remember as well maintained, with a west to east gain, but nothing particularly strenuous. I don't specifically remember Mt Franklin, so I looked it up, and the
Mt Franklin Trail from the shore/campground appears to be difficult, but you wouldn't deal with that from the ridge. I think I've been down that trail, which isn't the same as up, so I don't remember it.
The trails that go along the long axis are relatively mild. If you hike along the short axis they can be pretty brutal. You can get an idea with this map, but I would use a real topo map to be sure before planning a trip.
