Honestly I think you're going to get smoke with virtually any seasoning oils or fats. Even if you don't hit the bona fide "smoke point" you'll still get a bit of smoke naturally, be it from natural impurities in the oil, residual seasoning or flash rust on the pan, grime in the oven, etc.
Best thing you can do is just get really good at airflow maintenance.
I use homemade ghee, a very thin layer that I towel basically dry, oven for 1hr or so at 485F. I was doing it at 525F before but I find that the lower temp also works great.
The current photo was only with one cooked layer of seasoning, plus a new one that I had just toweled on which is what the photo is. I usually just go for two coats + top layer but plenty of people swear by more. Just never really seemed worth all the extra effort to me when cooking will give you the seasoning all the same.
That's correct. flax oil can work as a top coat over layers of more resilient coatings that don't become as hard (thus they bind better and aren't brittle). But there's almost no point to a final hard flax layer. It'll seem really nice at first but it'll still eventually scratch and chip. At least if you apply it over more resilient layers the end result won't be a need to start all over.
So their "scientific backing" to using flaxseed oil is that a quick Google search showed someone liked it, Chinese stuff says it's coated in flaxseed oil and they wouldn't say that if it wasn't good, and painters use the stuff because it makes a nice hard finish?
She claims that polymerization causes free radicals, and FRs = bad, but then later says you need to get oils that produce the highest amount of FRs for the best finish? It also says to go under or over the smoke point in the exact same paragraph.
What a mess. I don't see why I should trust Sheryl Canter over any other authority on the internet about which oil is good or bad. I don't like seed oils. I don't use them at home and I don't intend on using them for seasoning either.