Cascading (persist) with a mix of enhanced and not enhanced entities

We find out that it is actual not possible to use enhanced and not enhanced entities together.
Exist any limitations regarding the use of enhanced and non-enhanced entities?

We work based feature and want to load other bundles as an artifact from the Nexus. These are always enhanced. To enhance the entities during development is, because of our build environment, very time-consuming.
Unfortunately, we can not reproduce this with a small example until now. Sometimes it works.

According to the manual: "There is one case, however, where enhancement is required. Non persistable classes that access directly (not through methods) persistent fields of enhanced classes must also be enhanced."

In addition, although not specified in the manual, if a class is enhanced, its hierarchy (super classes, sub classes) should also be enhanced to avoid various issues.