Sounds about like any other supplement: don't take too much. If you look at the VITAL study, the primary benefits were to African Americans not eating fish twice a week.

Personally, I'll still keep taking a tsp of cod liver oil a day. I do this for potential neuroprotective effects - before I determined that I was not APOE4 carrier, I was taking fish oil in phospholipid form so it could get past the BBB transport defect associated with 4. Just cod liver oil for me now (way less expensive). One parent had Alzheimer's so it's a concern.

Also, there's some evidence that omega3 oil (2-4g/day) works as a treatment for hypertriglyceridemia, which I expect we'll be seeing more of as it's associated with metabolic syndrome.

https://pubmed.ncbi.nlm.nih.gov/31422671/

I wouldn't suggest a dose like that without medical supervision, though - but it's interesting.

Finally, I don't see any negative effects associated with alpha linoleic acid (ALA), but I'd expect that that's because we mammals aren't all that great at converting it into EPA/DHA - and some of us (e.g. me) are particularly bad at it. :-)