I know there is a lot of info out there on this but what is the latest status of European carriers on interlining (specifically baggage) on their own metal? J Award flight across the pond, but book the positioning flight separately on the SAME carrier. BA, LH, LX, TK, AF, etc.

Thanks!

EDIT: inquiry for both ways (if it would even be different) specifically on baggage through-check. Long-haul award from US to Europe and then a separate flight on same airline to final destination. Also on the return, positioning flight, and then separate ticket with same airline long-haul back to US.