There probably isn't a school that would take the approach you want.

Unfortunately it really is about learning the established systems and achieving a reasonable level of accomplishment.

It was a great struggle for me and I wish I had knuckled down earlier in life, as I would have had many more experiences.

The truth is that there are only a few performers who are that good at both theory and technique. Most folk are just reasonably good and have many failings. But they form the backbone of all the musical endeavours across the world.

Using: Dell 3268 i3, 8 GB ram, windows 10. Biab version 2017 standard package, no extras.