Utility layouts, or what we call "Dev layouts", are part of our process for building databases that are easy to maintain.
A dev layout is a layout used in scripts and in troubleshooting problems. Some examples of their use are:
When you add a table to a FileMaker database, a default layout is created for that table. Keep that layout as the dev layout, and name if after the table abbreviation. This makes it quick to find in databases that have many layouts.
Put all the dev layouts into their own folder and arrange them in alphabetical order.