The inability to change the maps, tiling, and texture details of the default materials directly limits what materials you can use for builds, especially those with a specific style. Currently, it is difficult to use all the materials in a wide variety of settings due to this lack of customization, and it can force you to leave materials off that you’d otherwise find perfect to use. The main workaround to this is downloading the texture for the material you want, manually mapping it if you want pbr lighting, and then setting it up as a material variant to be adjusted that way, which is a waste of time and resources.
If this issue were to be addressed via the material manager, it would allow for far more usability with the default materials. It would save time and let you not have to use extra material variants just to achieve a specific look.