I got the replacements for the blinkers I ordered: VLED 3157_21_A_CK.
You can tell the CK version because it only has 3 wires instead of the 4 wires that the standard version has. Otherwise, it looks identical to the red lamps (far right in the picture above).
Although these bulbs are big enough that they are touching the lens, they do fit, and appear brighter than the incandescent bulbs they replaced. I didn't try measuring these since my only options are off and blinking. It is difficult to measure the brightness of a blinking light.
I went in behind the bumper cover for the right lamp, but since subaru stuffed a filter in the left fender, I had to remove the battery to get at the left lamp.
All the bulbs are in place. The only shoe left to drop is if I get credited for the two bulbs I sent back that did not fit.