I now know exactly how I missed the spur trail to Southeast Peak.
Squak Mountain has many trails, and thus many trail junctions, and there is a sign for almost – almost – every one. Check out this junction (the left leads to SE Peak):
Not that SE Peak is a big deal. It has a slightly better view (see top photo, above) than West Peak or Central Peak, but Squak Mountain peaks are just not high enough to be above the tree line (SE is 1630 feet).
Anyway, now I know.
Some nice color along the trail:
About 7.75 miles, (including a little detour when I looked for an alternate way down but, when I got to the bottom, discovered they are building condos right up to the trail itself!) a good workout. Here is the track: