Any Legacy locomotive that uses the BEMF board will probably not play well with those equipped with the RCMC boards. Any RCMC equipped Legacy locomotive "should" play well with other RCMC equipped locomotives. I've also lashed up the older modular Legacy with the R4LC & DCDS with RCMC equipped locomotives successfully.
FWIW, only a handful of O-gauge Legacy have the BEMF board, I recall the LM Class-A, and the aforementioned 0-8-0. There may be a couple others, but not many. Lionel caught some flak for the BEMF, that was originally designed for America Flyer Legacy.