More miscellaneous CCE changes

[knelli2]

Proposed changes

Some more miscellaneous CCE changes needed for the updates in #6246. The more substantial changes will come in follow-up PRs.

Upgrade instructions

Code review checklist

• The code is documented and the documentation renders correctly. Run
  make doc to generate the documentation locally into BUILD_DIR/docs/html.
  Then open index.html.
• The code follows the stylistic and code quality guidelines listed in the
  code review guide.
• The PR lists upgrade instructions and is labeled bugfix or
  new feature if appropriate.

Further comments

[nilsdeppe]

LGTM, a few suggestions you can squash right away