Here's the goal:

Use a key schedule to apply materials to a door family. Not just text - actual materials.
Say we want all of our electrical room doors to have a common frame and door panel finish. We want this to both read correctly in our door schedule AND appear correctly in the building model. Without having this controlled by a key schedule, we are forced to either assign materials by instance or make a new door type just for electrical room doors and use type parameters if we want to keep it consistent. Being able to use a key schedule to set this stuff would be great.

Here's the problem:

Our door families are built with shared material parameters for door finish and frame finish.
As I have learned, key schedules can not include shared parameters.

However, I can make a project material parameter (assigned to doors) that can be added to a key schedule. There's just no way to tie the actual material to the door. It doesn't seem like there's a way to apply the actual material of a project material parameter to any kind of family. It's basically just useful as text.

Anyone else tried to do something like this? Thanks for your help.