Breaking infinite recursion in ProxyJump setting for wildcard host settings

You should be able to do this:

Host *.initech.biz !conclusions.initech.biz
    ProxyJump conclusions.initech.biz

This matches "*.initech.biz" except for "conclusions.initech.biz".

See this answer.

I think this works:

Host conclusions.initech.biz
    ProxyJump none

Host *.initech.biz
    ProxyJump conclusions.initech.biz

Settings for hosts that appear earlier in the file override those that come later.

The ssh_config documentation does not explicitly mention that none is valid value for ProxyJump, but it does appear to work on macOS 11.2.3 ssh, which is OpenSSH_8.1p1, LibreSSL 2.7.3.