When it comes to critiques/alpha reads, there's a big difference between a reader who doesn't write and a writer. I call the writer-readers "Wreaders", and I actively seek them out.
A writer reads widely and, often, critically as an essential part of the job. And nobody who reads like that can escape unscathed. You'll end up with an understanding of plot, style, and grammar. Not to mention a feel for words and a broad view of what makes for a good story.
On the other hand, plenty of people enjoy reading and read a lot more than active writers. They have a different, equally valuable insight that I can't replicate: the views of a pure reader. Somebody who wants to be astounded, captivated, taught, and above all Entertained. Someone who will spend an enjoyable time with a book without thinking about how they would have done it. Most writers can do that, but they're never sure if they have.
So, writers create superior critiques, but I'm not selling writing primarily to writers. That's not sustainable. Readers know what they want, but not how to make it. Taking the two styles of critique and putting them together should produce a quality piece.
My alpha reader strategy, then, is (1) submit the piece as soon as I've read it over and feel it's complete, then (2) get at least one reader and one wreader to take a look at the story so that I can apply these lessons in later pieces. Unless there's an especially obvious flaw in the critiqued piece that wants fixing.
So a time traveller goes back in time to 1945 and shoots Hitler in that bunker. Way to go, Time Traveller! Then he says to Eva Braun: "Dearest, I've loved you even though we were separated by temporal circumstances."
"Oh darling, I remember you from my dreams," she says and leaps into his arms, instantly redeemed from her Nazi ways by the power of love. Then they kill the bunker washerwoman (shooting Hitler is a Get Out of Hell Free card) and burn both of the bodies.
It turns out their daughter is accidentally sent back in time and, abandoned, becomes the washerwoman.
The above plot is still not as stupid as this:
2000 words? Yes
Book "Lived Too Long To Die" - chapter 10
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Reading - "The Planet Buyer" (Cordwainer Smith)