Agree/disagree: Capital purposefully underpromoted Brian's non-BBs productions to keep him working with the group.
I disagree that whatever record company underpromoted any/most/some of Brian's non-BBs productions, at least after Brian had produced a hit for the BBs. It doesn't make sense first of all to me. And it has been too long but I believe if you look for it you can find the evidence of vigorous promotion, stuff like surveys showing airplay on radio, trade ads, Universal Soldier was even on national U.S. TV [Shindig, Hullabaloo?]. I think supposed underpromotion is probably a rumor/excuse started back in the day when it was considered an inconvenient truth that Brian couldn't buy a hit outside of the BBs either. Brian could co-write a song that was a hit outside of the BBs but he could not produce a hit outside of the BBs it seems to me.
Edit: I said it had been too long [get it?]. According to YOUTube it was "Guess I'm Dumb" that was on Shindig. Maybe Universal Soldier was too but it was GID of which I was thinking.