I'm surprised to notice that I can compile a native image of an uberjar without direct linking and the binary seems to behave just fine. How is that possible? Wasn't direct linking mandatory? (using 22.2.0)

direct linking isn't mandatory but in some cases it can result in smaller binaries as the graal analyzer may notice some stuff can be left out

Do you reckon it is worth the effort perf-wise manually initializing more Java stuff at build time? Alongside the CLJ stuff detected by graal-build-time

It's not recommended to initialize anything at build time but for Clojure stuff we have to. For most Java stuff it probably doesn't get you anymore than a few ms of startup time