I use BH209 and like it. But this would not phase me in the least. I would load up and shoot some of the real deal, black powder. I use Goex FF in my traditional guns and my guns always go bang. How about going traditional this year and have a load of fun SL?
But for inlines if you must, I would consider Pyrodex RS to be a very superior sub powder.
Now remember this is all my personal opinion.