they should have a seperate batman for dcu, but he is only mentioned and showed in minor roles and cameos until the reeve batman triliogy (or duology) is finished.
have the dcu batman be long into his career, if he gets a. solo film just have it be the raid but set in Arkham, introducing most villains. maybe have a solo film fighting scarecrow (if he isn't in reeves universe), poison ivy or the court of owls.