make remaining service config constistent

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | minimal
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #78
| License       | MIT
| Doc PR        | -

A few _class slipped through, and there was some confusion in the DI extension that would lead to some class name configuration getting lost.