sledgehammer/customize-tasks
A list of extra tasks to add to customize Sledgehammer
If you want to build a customized Sledgehammer, the supported way to do it is to create additional tasks to perform whatever other customization steps you want to perform, and then add them to this list. They will be performed after the built-in extra package installation, and before discarding unneeded packages and conversion to a Sledgehammer image.
Any extra customization tasks should make sure that no extra bits wind up in the final Sledghammer image. THis includes removing any unneedeed documentation, source code, or additional packages and files that are not needed to support proper operation of Sledgehammer.