Throwing after the attack animation decreases capture rate

No, just pure luck, it all depends on the RNG, though.

Anecdotal

Do not mislead people by throwing your personal anecdotes.
I throw all these balls after the attack animation.

i find the opposite my catch rate is above the odds and i always throw to hit as soon as animation finishes

You are unlucky and that's all. I'm sorry. It's best not to read too much into it or you'll drive yourself crazy. Just keep hitting good throws and it'll balance out. Hopefully this week!

Which of the reported techniques do you think have merit?
- throw after the attack
- nanab/golden alternating balls
- everyone wait before hitting OK
- the phone shake

Every single ball I've thrown had been directly after the attack animation and I have a pretty good catch rate.

you have to take Lugia seperate.
Lugias Catch Rate is much lower than the other birds
I have 7/8 on Articuno 9/12 Moltres and 5/8 on Zapdos.
Which is little above average i think with about 10 Balls in average.
And then theres Lugia i have 1/4.
And its no surprise it´s so low because with fewer balls chance of catching Lugia is ridicoulisly low.
Just hit all balls and if possible grat or excelent and your good to go.
The rest is just RNG and Luck (critical catches i got 3)

Lugia and Moltres are harder to hit when they are coming out of their attack animation.

If that is your problem, then watch their idle animations for a while to learn when they can and can't attack.
https://pokemongo.gamepress.gg/jump-attack