It makes a lot of sense to make ContentTranslation work in the incubator. It should be an easy way to bootstrap new projects.
As far as I can see, not a lot of development is needed. To match the current way in which the Incubator works, it should do the following:
- Put the project code and the target language code as a prefix in the title when publishing.
- Open Special:CX in the same domain, because the target domain doesn't exist yet (or will it work as a redirect?)
- Have reasonable entry points.
- Be able to handle different project prefixes - Wikipedia, Wikivoyage, etc.