Setting up the DK6 Ergo on macOS

I bought the DUMANG DK6 Ergo, a split keyboard developed by a startup that allows you to freely rearrange the physical key layout.

There were a few issues when using this split keyboard on macOS, so I'm summarizing the setup steps I took.
Note: This article describes issues that occurred as of January 23, 2021. Since this keyboard is still under development, the situation may have improved by the time you read this.

Key Combinations

Problem

When using the DK6 Ergo on macOS, you cannot use key combinations that span the left and right keyboards. In Emacs, Ctrl+N moves the cursor down, but this requires pressing keys that are both on the right keyboard simultaneously. Pressing Left Ctrl + Right N does not work.

Solution

Install Karabiner-Elements. No special configuration is needed — just launching the app makes key combinations across the left and right keyboards work.