Ironically I actually walk without my toes in I wanted to get the saddle fitter out because Ninja's had the same saddle since he was 4, and I wanted to make sure the fit hadn't changed.
The part I bolded
jumped out at me....
Most humans are not "made", designed to walk with feet perfectly straight.
My orthopedist said that....we were discussing the human walking gait and he said only in countries where $$ is expendable do you find people have taken years of classes to walk a certain way, look a certain way or actually have surgery to change the direction the foot lands.
People are either toe-out or toe-in, with degree of that being small, medium or large in amounts.
People watch I was told and see what you see...then apply.
When the best riders in the world have toes "sticking out", some at huge amounts, I would not be concerned your feet "toe-out".
You can not compare the "look" of the human footfall to the look of the leg astride when it is expected to go round the barrel of near a 1000 pound animal.
The leg softly following the horses frame and that is
what is needed.
Look at pictures of those riders...really look.
And lastly, you beat on yourself for something you perceive to be a glaring problem, but when your instructor works with you this "perceived" issue is not what she concentrates your lessons to, this from all your instructors you've ridden with makes me think it may be more you think an issue than is a issue.
Have you just come straight out and asked the instructor if there is a problem with your toes not being straight ahead??
Now, your saddle........what above in blue applies to here.
Same saddle since the horse was 4....and the horse is how old now?
You have been riding in said saddle for how long?
And you have had difficulty in riding for how long?
And before this when you were a "recreational rider" we did not have such a problem...
See where I'm going...
Saddle fitter aside, if you have other saddles to try in appropriate sizes for your body, try them.
Ride in them and see if other issues you think you have have softened, have diminished or gotten more pronounced...that will give you some idea of where to be looking for issue...
Not only has the horse changed as he matured, so does the rider...