I use bbf all the time with the remote. In that case though, its basically manual focus. I set the camera up, activate the remote and then do my focusing with the bbf. When I do this, it is usually when I am shooting the moon or focusing on the bird feeder. I am also almost certainly recomposing too. So the bbf focus works out great for me. If you need the camera to focus at every click of the remote, you can leave the bb set to af-on and just quickly change focus to af-s. The default for af-s is usually focus priority so just making that quick change to af-s is all you need to get the camera to refocus each click. You could also set one of your U1/U2 to the focus settings you need. But if you are just doing group shots of people, I think you could just go with your regular bbf settings. Just focus where you want as usual, recompose if needed and join the group and click the remote.
edit: I am assuming ML-L3 remote here, I don't know how a plug-in remote would behave.