You write "Although Lion Rock is just a short distance away, the two peaks are separated by a difficult serrated ridgeline. (There are no entries in the summit register describing a direct traverse between the two peaks.)" I traversed from Lion Rock to Stewart, and found it mostly class 3, with some stout 4th class, with careful route-finding. Going the other way would be harder, since you would be going down the crux, which involves climbing on the NW side of the ridge to get around a steep step after the flat, block-maze part of the ridge.
"After the first glass, you see things as you wish they were. After the second, you see things as they are not. Finally, you see things as they really are, which is the most horrible thing in the world."
--Oscar Wilde on Absinthe