My wife has a favorite travel mug. Except it's not really designed for travel. It's a custom decorated oversized Yeti mug with a lid - but it doesn't fit in a car cup holder! A rational person would go to their 2nd favorite mug that fits in a cup holder when traveling, but logic doesn't always prevail. However, I promised her that I'd make her an adapter if she approved my purchase of a 3D printer! So win-win.
The mug adapter takes up a bit of space when it's not being used, so I broke it into two parts with a reversible quarter-turn locking mechanism so that it can take up less space when stored in the center console.
I recently saw a video from Prusa touting their new PrucaSlicer 2.0 with an easier to use Modifier tool. So I experimented with that too and put in some Texas Tech Double T modifiers that removed the outer perimeter to expose the Geoid infill. I liked the way it turned out. The Double T modifier is its own .stl file, so it's easy to leave that out or make your own.