Keeb.io should have you covered here with the Nyquist - 60% ortho split

If you want an ergo layout and can stick with a 40 they also have the Iris - 40% ergo split

I suggest you poke around their site. They have a couple other unusual split boards too.

Money/demand. Streaming platforms were not really pushing to license UHD content for anything other than their original productions prior to around 2019. That means that if what you want to watch was originally released prior to 2019 it is likely the series/feature would need to be remastered in UHD now. If the studios don’t see demand for a product in UHD they are not going to spend the money to remaster.