pull off the yeast first to dry hop, you don't want any other influences besides hops from that point, also make sure its completely submerged or other nasty tastes may surface
My last 3 IPA's were dry hopped in my Spidel 7 lier fermenter. I dry hopped for 10 days on all 3 batches. I have no issues at all with off flavors or anything else. I have also dry hopped in my 6.5 gallon carboys with the same great results. I use Safe ale 05 for my IPA's as my go to yeast. I have been brewing since 1980 and no longer use a secondary fermenter for the most part. On thing on the Spidel fermenters is that it does retain hop odors even after cleaning it with PBW. I just use it for IPA's. Good luck!
Failed to mention that I just dump my pellet hops (3 oz) on top of the beer in the primary. I no longer submerge the hops. Used to put them in a mesh bag with sterilized marbles with dental floss tied to the bag and out through the top of the fermenter. Dump them in now with same results!
good point! ... yes this would be fine for medium to low Flocculation or light tasting yeast like 05 but for a strong flavored yeast like English or Belgium yeast I would say no since the longer the yeast stay in the solution the more the beer starts to taste like yeast and not hops