How to Change Default Source Code Editor - MAC

I am starting on iOS development with both gaming and utility, and I simply don’t like Xcode. I’m okay with it for packaging and setting up for release, but while I’m iterating I would like to use, say, Atom for source code. The only answers I could find were from an old answer from 2014 that no longer applies to the current version of UE. I am from a windows background, but I feel more comfortable on a mac because of its Unix lineage and internal core. But Xcode has no theming save for the actual editor. When I have long coding nights my eyes hurt and it’s just clunky.

I’m not scared of scripting, after experimenting with the preferences where it says, “SourceCodeAccessSettings,” I can only assume there’s an applescript or such, but after much searching I can’t seem to find the necessary information or files. Any and all help is greatly appreciated. If someone finds this and can only point me in the right direction, I should be able to do the rest, but if there is some tricky dependency for Xcode in game programming I understand there might not be full integration.