Is it possible? Purely decorative Quarter-Pillars that snap in the corners of square tiles, making a full decorative pillar with 4 tiles, and also snap to decorative vaulted ceilings (corner ones).
It would add many aesthetic options and give people 100s of hours of in-game building time. Sell them as DLC or in bazaar, whatever, just make them.
Slice existing pillars vertically in 4 pieces, make them snap to square tile corners and have them provide no stability.
The expanded Turanian from the Bazaar set also has pillars that snap on corner tiles. They look good but don’t provide much support. The Stormglass pillars provide some support, but are huge.
Good news! You can totally already do this! It just takes a little bit of scaffold work to pull it off.
So - start with your square foundation that you want to “corner” with a pillar. Place a ceiling tile on that foundation to get away from it a piece, and get room to work.
Place a stair. Then, place a pillar under the stair. You will immediately see that you are offseting the snap point geometry because the pillar went directly underneath the stair to snap.
Anchor that pillar. Either into the terra firma earth, or perhaps another foundation that you will plan to clean up later. Then, do the same thing again. From your first offset pillar, put a ceiling tile and another stair. Then put a pillar underneath that stair.
You will find that the second pillar offset will be programmatically snapping to what would be the “corner geometry” of your original first foundation!
Then - simply anchor that second pillar offset into the ground, and then you can work with pillars and ceiling tiles to get your pillars positioned correctly.
You may have to experiment with placing the pillar first versus placing the foundation first, and the kinds of pillars you must use to make them all fit together correctly. Just know that you can switch up pillars to “make it fit.” And then you can come back to upgrade or replace those pillars with the decor choice pillar that you prefer.