You could try painter's tape or shrink tubing to smooth it out, although I haven't had issues with FG or double uni for tying braid to anything (whether backing or leader). I'm still thinking that you may need more braid wound on so that your casting distance isn't affected by the knot because the last bit of the cast will still have a layer or two of line covering the knot.
If I'm not at work or taking kids to their activities, you might find me on "The Rez" fishing. If not there, I could be in the garage working on my boat.