Well, Bolt (Parent DO NOT EDIT) should be the main parent style as you have it.
Then from there, what exactly are you wanting to do? The child styles I provided on the license page are meant to be "plug and play" in the sense that you just install them as a child to "Bolt (Parent DO NOT EDIT) and edit directly. No need for further child styles.
When you upgrade, you'll simply import and overwrite Bolt (Parent DO NOT EDIT) so the updates trickle down to the child style.