If you still need to override stuff - see how chrome can override content natively: https://www.youtube.com/watch?v=KxjGYcHZ_uI
You can try to use my half baked MV3 branch here, but it is untested and I won't be supporting it.
I don't plan to work on RO anymore so it's very unlikly this will ever be finished. I'm not the biggest fan of what MV3 is forcing upon people, so I don't have very much motivation to finish this. Additionally, most modern web development doesn't really need/work with an extension like this, and even if there are use cases, Chrome supports overriding content natively within their debug tools: https://www.youtube.com/watch?v=KxjGYcHZ_uI
Anyway, I apologize if this is disappointing news. You are welcome to build the extension yourself or use the source code in other ways, as it is under the MIT license. Maybe someday I will really wish I finished this and have a bad need for it - but until that day, this will be my last commit.
Thanks everyone for using RO.
I wish you the best.
Resource Override is an extension to help you gain full control of any website by redirecting traffic, replacing, editing, or inserting new content.