I've run into the same problem with a couple rackets… Wilson n4, and a Prince Air O. The last cross ties off at 11B which practically intersects the outside main. This leaves almost no room to tie off without rubbing against that main. I attempted a pro knot which lies under the main, but I can't help but wonder if a mishit to that area might put too much force on the knot and snap one or both strings. Unlikely, but possible? When I received the n4 it was strung one piece with the bottom cross tied off at 6B. However this time the client wanted a hybrid so 6B was taken by both mains. Has anyone else had to deal with this situation? I'd like to know a better solution in case I run into this problem again. Thanks for any tips offered.