All n-3s PUFAs are highly prone to oxidation. It’s more difficult to measure oxidation in krill oil because the color from the carotenoid -astaxanthin (a natural lipid soluble anti-oxidant)- makes a lot of the typical P-Anisidine tests read incorrectly. Typical fish oils later refined to make EPA all require some kind of antioxidant (AOX) like tocopherols (Vit E) be added. What you refer to as a negative on the part of the krill oil refiners is actually a positive - you want to keep the oils colder and frozen is even better to inhibit that oxidation process.
Most of the anchovy oil (biomass is usually estimated to be between 10-12 million mt except the population drops off during El Niño years, when the Humboldt Current upwelling —for the anchovy’s plankton food source, is stopped by equatorial kelvin waves making their way across the Pacific from AU) used to make EPA is caught and brought back to a shore plant to be rendered along the coast of Peru - by either artisanal or industrial boats (fish sits for much longer periods of time). The smell alone in places like Callao will tell you all about peroxide and Anisidine levels. Thus, the anchovy oil tends to have higher FFAs than factory ship processed on board fish oils. However, these peroxides and FFAs can be removed via several refining methods including short path distillation (SPD).
My only point, once again, is that krill oil is fine as a standalone oil for consumers (bioavailability/efficacy of phospholipids vs TGs vs EE vs rTGs points aside as I doubt we’ve heard the end of the debates because the research is ongoing) and could even be an alternative source raw material to make the EE EPA. Krill is considered to be the Mercedes of the marine n-3s. However, it’s not chosen, say by the likes of Marine Ingredients in API manufacture, because crude krill oil costs more than crude fish oil. Not because it is “inferior.” There’s nothing any more scammy to it than any other source of EPA/DHA. Claims made by the supplement world can be ridiculously unsupported, of course, but so unsurprisingly are a lot of marketing, investment, and valuation claims.