Sad to read that. I guess, that you don't have spare time for these experiments, but maybe once it would worth to try treating a few sheets to at least medium-dark brown. For example, TSP/Victas SWAT is still a thing - maybe recreating them should not be considered as a goal, but it would be interesting, how these plies could play in a blade.
Another topic: in my recent blade choices I found, that having a medium hard/hard outer ply is beneficial for my play, but only when there is a considerably softer ply underneath. I like how "thicker than very thin" Koto plays sometimes up to about 0.6mm, but my new favourite is Black Walnut and I also have good feeling with Teak as well. I will still keep playing around with these recently acquired blades, but I will definitely hop in your waiting line at some time to get something really fancy and well-thought to details (however, I need to wait if EUR/HUF change consolidates over time).
So, based on the wood-database, I will seek for outermost wood plies with 1000-1800 lbf Janka hardness, and around 11-15 GPa modulus of elasticity for my future blade to order from you.