Except when you're using multiple Spring libraries with XML config and are running on servers without access to the general internet.

I tried all the listed tricks to get the schemas into the shaded jar and none of them worked. So now I have to put big fat warnings in my README.md files that "yes, there's a bunch of errors on startup, and yes, there's a 60 second delay, but you can ignore it".

Spring Boot? I guess it doesn't produce a shaded jar, but I find the custom classloader w/embedded dependency jars to have fewer issues than shaded jars (of course, one disadvantage is you can't run proguard, if that's something you do).