But to me it seems like these would always be changed in "lock step", meaning I cannot really see a use case for wanting to override your ParameterMetadataRecognizer but not your QueryPlanFactory, nor vice versa. (Also, I very much dislike the name QueryPlanFactory when the thing in fact only deals with native queries, very misleading IMO)

I see where you're coming from and I'd agree when taking only native queries into account. In fact I named QueryPlanFactory that generic though in order to allow for the addition of other query plan creation methods in the future, should that need arise. I haven't thought this through till the end, but I felt this might be required for OGM at some point. I contemplated to add e.g. createHQLQueryPlan() right now but then I don't need it at this point and thus refrained from doing so. But it might actually make sense to add it and be done with it.

But I think we need to review what we want that to expose. In fact, I'd suggest we also review handling of native queries overall in light of lessons-learned as well as new requirements for OGM, etc.

+1