Remixed from my Ender 3 S1 side mount.
Added 2 more magnets on the back, enlarged the mount, and added a container for a dial indicator to use for bed leveling. The 2 magnets on the front for the dial indicator are probably overkill as it fits pretty snug. In fact, printing with .28 layer height, I needed to scale the model 100.7% for it to fit.
UPDATE: I've modeled a pegboard cradle for use with this holder. See it at: https://www.printables.com/model/643603-pegboard-holder-for-dial-indicator-mount-ender-3-s
The author remixed this model.
Added a holder for a dial indicator.