I'm teaching myself alto recorder. Since I'm mostly interested in jazz, I'm trying to practice in all keys from the start. My problem is with the right hand technique for the low chromatic notes. I found some descriptions mentioning a wrist turning technique, where one is supposed to turn one's wrist outward or upward, the fingers sliding to a position where they only cover a half hole. That more or less worked for me, but I seem to get better results and less right hand movement when lifting the finger tip to uncover half holes. For example, when playing from low F to low Ab, I lift my pinkie and straighten my third finger, such that the tip of it lifts a little and doesn't cover the other half hole anymore. While the wrist movement is similar to the supposedly proper technique, in this way, I manage to keep my pinky closer to its hole, and it seems to minimize movement in general. Also, I find it easier to slur these and similar movements (e.g. Bb to Ab) – there is less chance of squeaking and bending compared to when I do the sliding finger motion. Since I don't have a recorder teacher, I'd like to know whether such a technique is acceptable. I suppose the movement might be considered to lead to a less natural finger position or more tension, but it actually feels quite comfortable to me. Should I go on practicing it, or should I stop using it?
Rule #1 is to do what works for you. I don't do everything on the recorder the same way my teacher does, because I don't get on with some of her playing technique (particularly her method for left-hand thumb placement). You do have to know why you're doing what you're doing though, you can't just say "that looks hard" and do something else because it might be worth it being hard.
That said, you're clearly thinking in the right way about this. I've seen, roughly, three techniques for half-holing with the right hand.
I've seen people play well with all of these techniques. I tend to turn the wrist, but that's just what works for me - my hands and fingers are too big for #3, I end up smothering the 'open' side of the hole. Also, my fingers aren't delicate or precise enough to do method #2.
So you do what works for you, but I don't think you can describe any of these methods as 'wrong'. Some have different advantages, and you're right about keeping your fingers closer to the holes being a good thing. The trick with the wrist-turning technique is to do as little of it as possible else you can't get those rapid movements from F to Ab (for example) which comes up a lot in baroque music. Whatever you do also has to work well for tricky transitions like G->Ab->G at speed (like one of my grade 8 exam pieces, that took a lot of boring drilling to get that sorted out).
But just keep thinking like you're thinking, examining everything you do and experiment a lot and you'll come up with things that work. Do read the literature, watch videos, talk to other recorder players, but it's ultimately your hands, your recorder and your style of music and if you're producing a good sound and not artificially limiting yourself with your technique then I don't see why you should feel compelled to obey everything in a book.
My teacher would claim most of the books are wrong anyway. She keeps saying she's going to write her own...
In my opinion, what works for you is what works. Everyone's hands, wrists, and recorders are different. You seem to be analyzing your movements with great attention to detail; keep doing that. Practicing the 'best' movements will get them into your muscle memory and they'll become, if not quite second nature, at least third.
You may find that you'll use both kinds of techniques depending on what you're playing -- going up or down the scale, etc. That's perfectly fine. Practice jumping right to the half-hole notes from all the others, just to see what works in terms of your wrist movement.
Have fun, keep experimenting.