Beauty itself is still an act of observation and would be inherently subjective. The idea of an objective/universal beauty would need more explaining to me.

What if I find the idea of a single idea of beauty itself less beautiful than of subjective beauty? I like it when I grow to find something beautiful I once found ugly.

Hmmm. I guess that's another interpretive bridge to cross. I find material and immaterial as being interpretations of the same energy. You could view an atom as a collection of particles or as different states of overlapping or interwtines energy (quantum fields). You could see it as both. From here, I view Beauty and Math as conceptual, not immaterial, and creations of mind. We can create new concepts and make them real, but neither the angle nor Platos' perfect tree would be seen as objectively beautiful nor as perfect. Its 'realness' being unimportant.

I also appreciate the discussion. My personal philosophy is nowhere close to being complete, thoight out, or argued against, so this helps me sort things out for me too. I have something to learn from this I have only to gain.

With my work schedule it is hard to find time for large conversations.

My current view is like an but of a mix of different philosophers I have had some exposure to. Ayn Rand and Nietzsche come to mind, though I recommend Nietzsche more.

I can't point to anything specific with Nietzsche due to his writing style, but this link has a good interpretation:

https://ndpr.nd.edu/reviews/nietzsche-on-art-and-life/

If you wanted to look into Ayn Rand, I hear "Art and Cognition" is a good one to read, though her long lectures are available online as well.