I'm probably not the first person to think of this, but I modified how I lace my Busenitz and haven't had any issues with the tongue slipping. I have worn these almost daily for a few months and have skated in them a few times.
Hopefully it's not too hard to make out in the pictures, but I simply poked a hole in the tongue itself at the point closest to the nearest lace hole and laced through it.
That's all.