Grafting incompatibilty of Sweet Chest species

Are there any problems grafting Castanea crenata (Japanese chestnut) onto Castanea sativa (European chestnut)

If the graft took, but there is along term incompatiblity problem, would it be best to plant out with the graft below soil level, so Castanea crenata (Japanese chestnut) would root and take over Castanea sativa (European chestnut)