I ask because I hacked up something a couple years back to let me manage files in ~/.ssh/config.d, plus a Makefile that produced ~/.ssh/config from them and a set of shims for OpenSSH commands which would run make before running ssh, scp, etc., to make sure the live config stayed up to date with changes in .d files. But I haven't used that pile of shell scripts or looked at it in a while, so it's probably started to smell a bit, and it would therefore be nice if this were a thing OpenSSH itself can now do.
I ask because I hacked up something a couple years back to let me manage files in ~/.ssh/config.d, plus a Makefile that produced ~/.ssh/config from them and a set of shims for OpenSSH commands which would run make before running ssh, scp, etc., to make sure the live config stayed up to date with changes in .d files. But I haven't used that pile of shell scripts or looked at it in a while, so it's probably started to smell a bit, and it would therefore be nice if this were a thing OpenSSH itself can now do.