Another trick to help with this is to mill the wheat and combine it with the rest of the grains and then run that through the mill. This is what I do and I don't have any issues with efficiency on beers with wheat.
Bumping this thread because I'm curious how yours turned out. I just brewed one today with a 15 minute boil. Cooled it to 110 and pitched lacto which I'm holding at 100 ambient. Plan on cooling and pitching Wyeast 1007 in a couple days.