An application with a few thousand virtual threads seems this in the VM.native_memory output

Thread (reserved=53MB, committed=6MB)
             (thread #53)
             (stack: reserved=53MB, committed=6MB)

"thread #53" is a bit confusing here as it's very different to the number of j.l.Threads in use. Given the output is native memory usage then maybe the prefix for this line should say that it's the number of native thread stacks.