I agree that there is not consensus in the scientific/medical community about this. You can find MDs who will advise avoiding linoleic acid as a top health prioty (i.e Paul Saladino) and other scientists who do not agree there is sufficient evidence to indict seed oils (i.e Andrew Huberman). Likewise, you can find all sorts of studies.

To address your point about the study I linked -- I think you're mistaken. The LA group did have a significant increase in 8-iso-PGF2alpha urine metabolites, and decrease in nitric oxide metabolites. From the study:

> Urinary excretion of 8-iso-PGF2alpha was significantly increased after the LA diet (170 vs 241 ng/mmol creatinine, P=0.04), whereas the urinary concentration of nitric oxide metabolites decreased (4.2 vs 2.6 mg/mmol creatinine, P=0.03).

also

> In conclusion, the high-LA diet increased oxidative stress and affected endothelial function in a way which may in the long-term predispose to endothelial dysfunction.