Discoverability is definitely a problem - part of that is a docs issue, since test.support is currently the only one mentioned in the prose docs.

One advantage to moving to a support subpackage is that we can lose the "helper" suffix from the names, while still allowing thematic divisions.

So, for example, we could have

# support.py -> support/__init__.py
import test.support
# script_helper.py -> support/scripts.py
import test.support.scripts
# Other possible additions
import test.support.imports
import test.support.network

Even without updating the prose docs, this would help discoverability a lot by having a much smaller directory listing to scan for useful support code. At the moment the general purpose helper modules are mixed in with the tests

I agree with Antoine that we're probably better off handling this as a refactor post-release at this point, though. I'd hoped to have the time to devote to it beforehand, but there's user facing stuff that's higher priority right now.