Nice! The denser negative does indeed look perfect for carbon transfer. No doubt it'll print nicely.
I notice the shouldering behavior of the film in this particular instance isn't as bad as I'm used to with xray. In my hands it had a habit of shouldering off pretty badly, reducing contrast in the highlights. This was the main reason I abandoned it for regular photographic use.
I’m very interested to know why you chose to test this pairing? BT’s belief was that his 2-bath developer restrained highlights. If there was a shouldering problem, like @koraks described, it would presumably be at its worst with this developer.
I have used BT2B contentedly with conventional films for several years now, and because I find the resulting negatives easy to print, including intense highlights like electric lights, I’ve accepted the theory. But I was really surprised by the result that @aparat got with Tri-X in BT2B: no evidence of restrained highlights at all. (I can’t link to it here because all links on Photrio to his plots seem to be broken.) I suppose the outcome may depend on how you use the developer (agitation), but its properties seem something of an open question at the moment.
I still have a couple hundred sheets of 11x14 X-ray film left over, I should probably cut it up and use it. I used to cut it up for my 5x7 but haven't done so in a while. My 8x10 sez it would like to try some.