I understand your frustration with spending time and not seeing lasting results.
Conscious of your movement patterns and posture is an important first step.
Now that you are aware of where changes are needed you have more direction on where to go.
Spending more time in the bottom of a squat with incorrect position does not help.
This reinforces incorrect positioning.
An acceptable turnout is 7-11 degrees.
As you are working through your restrictions use a depth where you are able to maintain idealized position/technique. At first this won’t be full depth. Working within where you are at.
Proper technique/movement patterns first, then begin lowering the depth slowly.
First goal is a parallel squat with proper form.
Write down the what you need to do to get to that point.
Work toward achieving that everyday.
Here is an example where JStar uses a band when doing the 10:00 squat test.
Episode 120: Ten Minute Squat Test #4
Are you seeing improvements in the hip flexors, psoas, and quads?
If using the supernova is super painful then use a different tool.
Should not be going into the pain cave. Need to always be able to breathe.
I’d recommend a Yoga Tune Up Alpha Ball or Therapy Plus . When the tool that you are using is too hard you’ll be inducing a flight or fight response, chances are you are too deep. You’ll scale back up to the supernova in time.
Have you voodoo wrapped your hip flexors and/or quads?
If you aren’t seeing improvements with the work you are doing its time to take a new approach to the situation.