Comment by thebitstick

Orion is another WebKit browser that makes WebExtensions installable via its own extensions API. It's not perfect but it's miles better than anything Safari has and allows for existing Firefox/Chrome extensions to be installed. It only supports MV2 and won't be affected by the MV3 changes in Chrome world.

If DDG wanted to they could replicate this work to allow for MV2 WebExtensions to be installed.