FWIW, it doesn't handle your use case of Layer 4, but for the people at Layer 7, another option is good ol' Apache: it is so flexible and extensible it is almost a problem, people tend to not know it long ago went event-oriented with mpm_event, and it supports ACME internally (as a module, but a first-party module that is seamlessly integrated). (I do appreciate, though, that it is critically NOT written in a memory safe language, lol, but neither is nginx.)