But it isn't well researched, that's precisely the myth that in these areas there's solid science with precise thresholds! I've read your article and it includes many gems such as max line length of 80 cpl, which is useless to determine whether a line of 150 is bad. Or it suffers from a universal issue of this kind science - tiny sample sizes or unrepresentative composition (the perennial college student, here goes your reading skill diversity relevant for making broad conclusions about human eyes). Or it ignores that length isn't everything, there is also density (some research did vary it, but even then it was only doubling), which a simple cpl count used in many cited papers doesn't measure
And the main factor against long lines is errors returning to the next line's beginning.
First, what's the well researched level drop between 130 and 150 for a person with a high reading skill level?
Then, have they "well researched" such simple typographical guides as the varying line widths (check out the layout of this very article, note that it's not rectangular, but one side is continuously growing in length, cool trick!). Or having some alternating line markers at line beginning/end to make visual match easy (similar, but not identical, to tables where you have full line highlighted)?
Maybe the most efficient reading is at line length of 333 with line guides and semantics guides (like those bionic reading extensions) at higher text density? You could be missing out on +10% speed bump and 4% comprehension level! And the head movements would also reduce muscle strain from a prolonged fixed head/neck position! Or maybe the very best is even higher 1234 but requires some curved ultrawide monitor to fit you whole peripheral vision and immerse you in the text without other visual distractions? I'd be curious to know what the real scientific eye limits are when it comes to reading.
But also efficiency isn't the only important metric for casual reading of web blogs, while a lot of research focused on that. There was some research about user perception that found no difference between line lengths. So there is that.
I also don't get why would you ever need to adjust window width per website? Say, for me the best line length is max 133 at font size 14 and char spacing X. So if I set my window at about this width so that no more text fits, and it reflows, I'm set. Yes, there are sites that disrespect user font size preferences, which would require zooming (or reading plugin), but this true regardless of the max width preferences, and also they would disrespect whatever the width guidelines are.