Isn't this grammar overlapping with the other た所 under 所だ. There it is translated with "Just after A, B", which is pretty much the same like the one here.
Sairen - the meaning is a bit different; clarified it a bit, and blended them into one page (there's now 4 meanings on this page: 3 from one, 1 from the other)
Do you think that needs to be listed as an additional construction? It's still the 'ta-form + tokoro', just that the ta form happens to be on a helper verb, and not the main one.
Unicom stays "よく使う形:‾てみたところ" so yes, add it under "Additional usages" would be wise. Other than that, it has more of a "when" feeling, instead of "after".
Ugh, it did that to me the first time and I swore it fixed it the second time. For some reason, if I write in Japanese, it won't show up. My question was what is the difference between point #1 and ようとした (You toshita) ?