Custom content will not appear in ZBrush until it is loaded into the program, even if placed on a UI the Startup folders. When you save a custom loaded through Lightbox on demand. Save a custom version of the brush you want and load it on demand from Lightbox or add it to.
If you are using version 4r8, please make sure you have ZBrush 4r8 installed with the Patch 2 upgrade. ZBR file from the project folder and overwrite the existing ones. Using the Save UI button you can save multiple configuration files and load them when needed using the Load UI button.
