Well after a year of restacking my daughter's cute Ikea DUKTIG Plate/bowl set on top of each other (having to un- and restack at least twice a day), and several conversations with my wife about where I think we should stack them and her saying she knows where we will stack them, I found a happy solution.

I never like the under shelf attachments for cabinets as they never utilize the back of the cabinet. This never made sense to me as most shelves are removable so you can access the back of the shelf which would then utilize the back wall for weight support.

--IMPORTANT DISCLAIMER--
Use/modify at your own risk.

Although it could easily hold four saucers, perhaps adding some eye hooks underneath, could make a nice teacup set holder. But if you are inclined to something a little more specialized, I'm including the Fusion 360 file if your shelf is thicker/thinner or you want to modify the caddy's dimensions. I would note that I do not know what the shelf's weight capacity limit is. I used PETG which can support more weight and is less likely to delaminate under stress, also extra parameters for walls, but after testing the flex I think it would have worked fine with PLA too. Also, I already had my translucent violet PETG in the printer... so why swap it out?

Cabinet shelf thickness: 20mm
Undershelf caddy holds about 190mmx190mmx78mm volume of dishes

Materials used:

• Mounting tape (the two types I use for most projects):
  • Scotch Clear Mounting Tape, 1" (this stuff is removable if needed and what I used in this project) - https://amzn.to/2Yv3C2q
  • 3M Scotch Mounting Tape (a bit more permanent) - https://amzn.to/37ZuZoo
• Ikea DUKTIG Plate/bowl set - https://www.ikea.com/us/en/p/duktig-plate-bowl-40130165/?gclid=EAIaIQobChMIk6eE57md6gIVFozICh3qAgh8EAQYASABEgJlyPD_BwE
• PETG
  • I used Prusa Translucent Violet
  • Yoyi is a good alternative in the States - https://amzn.to/3hRHmaV
  • Yoyi PETG in black is very nice as well - https://amzn.to/3fWhE2T