David, I don't disagree with you at all about quality oil applied in the correct amount to clean parts. Sounds like a recipe for success to me.
But, I like to experiment. And I like to push the envelope a little. I jumped on the rocket fuel bandwagon when it first became available, and like everybody else, soon discovered that once per year was nowhere near often enough. I tried a lot of different lubes over the years, before settling on 321.
TSI has been around long enough now that you would think most of the disinformation has been answered away. But it has not.
Comparing WD40 to TSI321 is like comparing fingernail polish to epoxy. They are two different products, designed for completely different uses.
WD40 was designed to displace water, not for use as a lubricant. TSI321 is a synthetic ester. Esters were developed as lubricants for high speed, very high temperature applications. Originally, it was the development of synthetic esters that made the jet engine possible; which is not at all to the point.
TSI301 is a penetrating lubricant. It is 321 ester mixed with a solvent. The solvent is harmful to some plastics. They do not tell us what the solvent is, nor is it listed which plastics can be harmed by it. Again, doesn't matter to me. I use 321, which has no solvent. I'm starting with properly cleaned parts, and don't need the penetrating, cleaning properties of a solvent.
This particular ester is a molecule with polarity. In a nutshell that means the molecules link together and bind to metals. This provides long lasting corrosion protection along with excellent lubrication. I find this to be just what the doctor ordered for spool bearings, and for levelwind lubrication.
When used on the levelwind parts, grit does not stick nearly as much, and can be simply rinsed away with fresh water; which does not wash away the lube. Try this sometime. You may be impressed.
In fact, if you PM your address to me, I'll send you some. I have a good sized container of the stuff, and, being an old fart, I may not live long enough to use it all up. I'd be happy to send you a sample. Like I said, it ain't magic, but it do be pretty darned good stuff.