Thanks Unearthlywhales, your answer gave me an idea that does the job. I ended up coming at it from a different direction after reading your response. Rather than specifying the values in the materials, I set the values up as variables in the BPs and then used those to set the parameters, so the starting / desired value is set in the BP without ever setting it up in the material.
I’m obviously too tired to be trying to figure things out on my own tonight lol.
Thanks again! I’m going to look further in the MP collections as well, but that will have to wait till another day.