I'm not the OP, but Orion supports extensions from both the Firefox and Chrome ecosystems. It also supports the WebRequest API in blocking mode, meaning you can use uBlock Origin, which you can't use at all with Safari.
Although the extensions will install, good luck getting them to work properly. Even the ones that the browser recommends to install, they are extremely buggy still. I hope one day they’re able to get extensions working better.
If Orion is based on webkit, what other advantages does it offer over Safari that you found?