"Are the shortcuts off trail?"
Yes. One good one cuts from Upper Cathedral Lake up to Tressider Peak and down to Sunrise Lakes.
One goes from the south side of Columbia Finger, turns north through Long Meadow, and up over the hill to Mildred Lake. Then from Mildred, you can easily wander over to Sunrise Lakes.
From Tenaya Lake, we would go up the hill by trail to the west end of Sunrise Lakes, then over to Mildred Lake, then straight down to Tenaya Lake for the return.
Hardly anybody goes to these places since there are no complete official trails.
Or, to quote Yogi Berra: "Nobody goes there anymore. It's too crowded."