i never rack with airlock activity still going. that's a noob thing. it decreases the yeast count when yeast is needed still; otherwise, the yeast would be still. if you're looking at 7% or thereabouts, like two-hearted is, i'd probably 3-week primary, 2-week secondary it to let it smooth a little. there's a lot of talk about primary vs secondary, and lots of people will chime in either way, but that's just me. no, a blow-off vs airlock shouldn't cause any problems, either
Two things are infinite: the universe and human stupidity, and I'm not sure about the universe.