I really like Leo Gray's "easier remix" of the OpenGrid Removeable Command Strip Mount, but for attaching adjacent panels, I wanted the ability to snap a single mount into four adjacent grids.

Here's my solution. It's an extremely tight fit, but it works. (EDIT 21 Mar 2026 updated model; it should fit better now.) Don't force it into all four holes at once. You're better off pushing it into 1-2 panels at a time. There's a two-snap version at https://www.printables.com/model/1553110-double-command-strip-mount-for-opengrid

Use Leo's hand tool (not included here, as I didn't change it) for easy opening and closing.