Block and fill the gutter using the Seawall tile for Hextraction! Seawall's wall is the trigger zone - when triggered, you'll plug the hole that ball went through with a random tile from the pool. Note, according to the default wording of these rules, if the ball falls into the hole from itself it doesn't overwrite itself with a new tile. At high enough speed the ball can make it through the straight channel, but typically this will serve as a trap for passerby.
Rules Card Text Trigger: Spawn a tile in the empty slot this ball fell in.
Printing / Assembly Instructions Print the wall, bottom tile piece, and top tile piece. I had a little bit of stringing in the bottom model, I might recommend a tiny bit of support under the middle ring overhangs. Click fit the wall into the bottom with the star side facing up so it is visible from above when closed. Glue the top tile piece to the bottom, and you're done! For the rules card, if printing with multi-material: drag both the base and detail STLs into your slicer simultaneously, loading it as one object with multiple parts, just like the lid. Assign filaments as desired. A single piece STL is also provided.