I wouldn't want to chance it. My broc (well, calabrese) got massive in the twinkling of an eye last year. What does it say on the seed packet (mini caulis?). I find some seed packets spectalularly unhelpful, but I have never grown mini ones so I can't advise you. All I know is that some are picked early, and some grow at the same rate as normal ones.
I already planted my brassicas from front to back: caulis, calabrese & broc, sprouts. Sorry to be a smart-arse. LOL. If it makes you feel any better, I put my turnips elsewhere not realising they were brassicas! DUH! ::) Another growing season, another mistake. One day I will get the hang of it!