If you take Apostacy in Bladedancer it would convert your Dodge Rating to Glancing Blow but the Glancing Blow you gained from this conversion would not be converted to Block Chance if you have Corsair’s set on. Corsair’s set would however, work in every other scenario such as converting the flat Glancing Blow you gain from Rogue/Bladedancer and also other places like Dusk Shroud procs.
Edit: After testing the above is correct.