It is possible (I just did it) - but it is not very practical.
You need to follow the trail of CALLed macros, from your door frame object to the custom door object you create.
Every CALL for the door panel you will have to pass on the door panel material.
Eventually you will get to the "Door_Panel_Collection" macro that gets re-written every time you create a new custom door panel.
You will need to crate a new material parameter for the door panel material.
The good news is that this will keep the new parameter even when it is re-written (it just gets amended).
In the 3D script of this "Door_Panel_Collection" macro it will call the custom door panels.
Again you have to pass on the door panel material parameter in each of the CALLs.
Now each of these called door panels is an object (macro) that you will need to open.
You will need to add the door panel material parameter.
Then in the 3D script find everywhere that it uses the default hard coded material from when you created the panel, and swap it for the door panel material parameter.
When all of these are saved you should be able to swap the door panel material.
You will need to do the same if you have multiple materials (glass and trims).
Everytime you create a new custom panel, you will have to add the material parameter to the CALL in the "Door_Panel_Collection" macro (because there will be a new CALL added to it.
You also have to open the actual custom panel object and add the material parameter to it and fix up the 3D script.
It is not impossible, but it is messy.
I get the feeling that you would need to go through the whole process from the "Door_Panel_Collection" macro onwards in every job, as this is saved in your user profile somewhere (not the embedded library or the loaded libraries) and the custom panels are saved in the embedded library (although these can be exported into a loaded library).
Just to prove it is possible attached is an image of one of my standard door objects with a custom panel and the material controlled from the door object.
It may be more complicated with Graphisoft doors as they call many more macros (I don't use them).
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11