By defaultcoder config-ssh writes to~/.ssh/config, the problem is that many other tools also writes there and ends up being quite messy.

Ideally it should edit a separate file like~/.ssh/coder/config and then have an "Include" to point to

## START CODER INTEGRATIONInclude "coder/config"## END CODER INTEGRATION

Alternatives

Currently you can use--ssh-config-file

coder config-ssh --ssh-config-file~/.ssh/coder-config

But then you can use this config file or update~/.ssh/config

ssh -F~/.ssh/coder/config coder.test

So having a convenience command line option to add the missing "Include" to~/.ssh/config