Really liked the Cubistand model from sdmc (Thingiverse origination), but needed it to be Gridfinity compliant. Slapped it on a 2x2 Gridfinity bin base and removed the embossed text to increase print success and now it can be added to my collection. See original link for assembly instructions / options (e.g., optional post count/positions).
Available with and without magnet holes.
Pictured here in single support post configuration, can place a rod in each corner for added support.
The author remixed this model.