I don't normally do form breakdowns in here. but lets go over some telltale signs you're muscling and trying to do a spin and throw level of throw vs a braced throw.
To start it off simply, you're not throwing from a brace, it just looks like you are.
Your brace is collapsing in this frame here as you start to hug yourself.
So it looks like you braced here, its really hard to tell much more because you posted a slow motion video. 60fps real time is better btw. It's best to be able to see the speed at which your moving. With youtube i can go frame by frame really easy to watch the details especially at 60fps.
So your brace kinda falls here and what you're doing is throwing your shoulders. How can I tell? Because your arm starts to collapse here.
/insert hugging yourself sidewinder video.
I'll address all the big issues here though with this image as its pretty overall telling whats going on.
Whoa, you're saying, thats a lot of lines.
The 90 degree rule isn't a hard rule, but if you're collapsed and not close, you're never going to generate power.
So, here you are shrugging your scapula and trying to yank the disc around hugging yourself.
Gotta get that elbow forward and get the wrist loaded. Your wrist in this photo is broke open, so your dragging the disc behind your hand.
Disc between chest and hand.
Where you decide to pocket the disc isn't something i'm going to say where, but getting your shoulders relaxed and that elbow forward is where you should probably start.
Let me explain.
What most likely happened is you tried good info on getting your lower body working, but there wasn't good enough instruction to get your upper body to move along with it. WHich is the jist of what I'm seeing from the method. Not really overly sure what the guy is talking about half the time anyways, so props to you or you decoder ring for figuring it out.
So what happens is we throw and were like "okay i guess i gotta add some sauce" and we end up ruining all our lower body form as we try and yeet the disc further and our upper body collapses.
So, focus on getting the shoulders relaxed and dont yank the disc, just try and get the disc up into the pocket and swing relaxed and easy.
This is where stuff like the windmill and some other drills that sidewinder has come in really handy.
I usually teach my version of the beto drill for this.
Sidewinder will have to link video's he thinks appropriate. His catalog is to complex for me with his weird video titles. I'm just dumb sheep shearer. Can't internets at all.