OK, we have to ask how much the heat actually matters? With the right oil, which will continue to lube properly in high temperatures, is there more damage being done by it running hot?
Having asked that question, I have to say that the 2nd BB that was fitted to my car was quite quiet, but after an hour or so of running at cruising speed, it would gradually get noisier and noisier, until it was as loud as the loudest BBs. Once cooled down, it was quiet again until the heat built up.
Perhaps they need some sort of cooling fins and either ducted cold air or a fan?
