Load it and shoot it.
A couple of folks in this forum have used BH 209 in Black Diamond rifles with no problems. The biggest drawback of the TC plug is the breech area gets pretty dirty. Cleans up with Hoppe's #9.
I have a BD XR .45 and I used regular Winchester 209 primers. Another poster on this forum, Calvin from Rising Sun, MD, also had good results with his BD.
I think a better primer holder could be made for the Black Diamond for use with BH 209, but I don't know if TC is interested.