I think for uniformity's sake I'd make sure it's a homo-black bull.. I would think they'd make good momma cows, but leave something to be desired for feeders.. bred to a balancer or such may make a good feeder. Shorthorns are known for taking a long time to finish and needing a lot of backgrounding to fill out big frames, the BA may help with that a little, but i'm sure some of the calves will look just like momma as far as frame goes.
Be interesting to know how it goes if you try it anyhow.