Thanks you so much for the tests. I have done a similar test like yours and the result is listed at https://github.com/networknt/microservices-framework-benchmark along with some other microservices frameworks.
light-4j throughput 1.3 million/second with latency 2.36ms
Springboot throughput 32K/second with latency 83ms
Without even consider that spring boot uses 5 times more memory than light-4j, you need have 44 VMs running sprintboot to have the same throughput of one instance of light-4j. We did a guess that if you want sprintboot to have the same latency 2.36ms with 1.3 million throughput, you need several hundreds sprintboot instances.
Above benchmark is maintained by our team and source code is available to run these tests on your own. There is third party testing available.