I wouldn't sweat it. Different phenos can fade at different rates. Everything looks healthy and the flowering looks closer to 4 weeks to me. The plant naturally moves nitrogen from its leaves to the buds, because it is easier for the plant to utilize. When plants are in the ground they can...
Here is the story of the Iranian itself. I suspect it is related to THumper's. https://oregongreenseed.com/shop/oregon-green-seed/dgs/iranian-early-flower-bx2/
I've grown a cross of an early flowering Iranian x 70s Oaxacan. Potent hybrid that finished in mid Sept. Here is its story. https://oregongreenseed.com/shop/oregon-green-seed/dgs/oaxacan-iranian/
Happens sometimes! Got a buddy that has Rainbow Beltz almost done outdoors in Oklahoma. Started from seed indoors in late March and placed out side mid May.
Dagga Gardens is legit! Peter has done a lot of Youtube interviews with prominent breeders and hooks you up on your seed orders! I also recieved a pack of The Hard Core from Harti, interesting, little known breeder from New Mexico apparently.
I've run The Work, both his original and the F2, Salvisa, Beshear and have his Work Cola going now. Actually had The Work state tested and all 3 phenos came in north of 25%. The plant to the right is The Work, from September, 2022.
This guy grows outdoors in Michigan! I've grown his gear several times outdoors in Oklahoma and had some of my best results ever. He is an outstanding breeder as well! https://seedsoflove.world/product-category/mi/lymerisingfarms/
Its just a normal fade at the end of its life! I wouldn't feed it anymore. I have found that outdoor grown plants often finish quicker than indoor, especially when it is hot. I wouldn't be surprised if it is done in about 2 more weeks, but there is no way to know for sure. Just let it continue...