I've used Power Pro and Gel-spun with no issues for false albacore. For the backing to line connection, I made a double loop in the braid (bimini twist then fold the loop over and do a surgeons knot) and loop-to-loop connect it to the fly line...going thru the fly line loop twice to spread the pressure out over a larger area of line surface. Doubled loop in backing and running it thru fly line loop twice seems to work well. Tips to prevent slipping work well...as does putting on a few feet of dacron backing first.
If you are using the reel for freshwater and it's not likely you'll be run into your backing....knots and connections may not be as big a deal as it can be in saltwater. On freshwater reels I see a lot of non-recommended "stuff" used as backing...trotline, masons line, nylon cord, old mono etc.