I have not tried it, and I make a lot of BL bows. I have only backed BL with rawhide and find that combo to be great. Since BL is so strong in tension to begin with, not sure why you would bother with a boo backing. Seems like you are asking for belly trouble. As it is, I usually trap the back of all my BL bows, or else the belly frets. Please let us know how it turns out - - always looking for new ideas. If you do decide to give it a go, definitely go with a very thin boo backing - thinner than an eighth, I would think - or just use raw hide . . . .
Russ