The flies with hooks with the turned inward tips look to me like circle hooks. I’ve mostly seen them used in larger sized hooks for bait fishing. More specifically for salt water fishing.
However, an internet search for - circle hooks for flies, or circle hooks for trout flies. Turns up quite a few results. Many were again made on larger hooks for flies for big salt water fish. But there were also many smaller ones likes these.
From the featherandfluoro dot com website in S. Africa, for what they call - poly-nymphing.
And on flyandfin blogspot
http://flyandfin.blogspot.com/2011/01/pearl-tag-caddis.html
Circle hooks are claimed to provide easier hook sets, almost automatic hook set, due to the angled tip. However, I read mixed opinions about them. Some bait fishermen report more fish die from being gut hooked with them, and the hooks difficult to remove. Other websites say circle hooks reduce gut hooks. Hard to know who to believe. Yet the following website reports - circle hook flies are good for catching not keeping. But while that author starts off writing about the introduction of smaller circle hooks being a benefit. As you read on the smaller circle hooks are size 2/0.
https://www.outdoorlife.com/articles/fishing/2007/09/hooks-come-full-circle
Oddly in the search results for - circle hooks trout flies. There were also several results for - hookless flies.
https://www.fieldandstream.com/articles/fishing/fly-fishing/how-fish/2009/03/look-ma-no-hooks#page-2
https://thelimpcobra.com/2016/09/30/hookless-fly-fishing/
http://fliesonly.blogspot.com/2009/10/new-fly-fishing-method-that-uses.html
Maybe an idea that didn’t work or find customers. The Moffitt Angling system referenced above seems to be kaput.
Anyway, the articles about hookless flies, reminds me of the forum thread about the Mystery of the Labyrinth Hook from almost a year ago. Fishing to get the take, but not actually hooking the fish. Similar to the Plains Indians idea of Counting Coup to gain the highest honor.
https://10colorstenkara.com/t/mystery-of-the-labyrinth-hook/211/25
Or what this angler in Switzerland calls - Teasing.
