I’ve never used Relay so I couldn’t say for certain but I believe it wouldn’t work in that case. IIRC the Relay app was updated to the subscription model of access like reddit was trying to force on everyone. If that’s the case being a mod won’t change the hardcoded behavior of the updated app.

This workaround works with Boost without any kind of updating or patching, so if there’s a third party app that did what Boost did (stopped updating but left the app otherwise intact) there’s probably a fair chance the same process will work. Any of the apps that continued to update or deleted API keys would have a much harder time I’d imagine.