The palette can be controlled in a number of ways. As well as renaming and reordering the drawers as described in Viewing and editing stitch libraries, you can pin open certain drawers if they contain the stitches you use most frequently.
When you open a drawer, a small white pin/tack icon appears in the title bar.
Click on the pin icon to pin the drawer open. The pin will change direction and turn grey to show it is pinned open This means the drawer will stay open even when you open and close other drawers.
Click on the pin icon again to unpin the drawer. It will now close when you click on another drawer to open it.
You can have multiple drawers pinned open at the same time and, as described in Editing a user stitch library point 11, you can set a preference for the software to open, and pin, specific drawers on start up.