> The programs that need it are mostly the ones nobody is maintaining

Yes, as I mentioned, it should be kept around for this but off by default. Make it a sysctl param, done.

> TCP_NODELAY can also make fingerprinting easier in various ways which is a reason to make it something you have to ask for

Only because it's on by default for no real reason. I'm saying the default should be off.

If nobody is maintaining them, do we really need them? In which case, does it really matter?

If we need them, and they’re not being maintained, then maybe that’s the kind of “scream test” wake up we need for them to either be properly deprecated, or updated.