His growths are 0% for every stat. You will get either 0 or 1 stats per level up. (I don't know if 0% growth stats get affected by the rigged "always 1 stat in a level up").
And if I'm not mistaken I recall seeing a post either here or somewhere else that showed that the BK's stats reset even if you give him stat boosters or raise his weapon rank. His lance rank was raised to SS, when he appeared again he had it back to S. However I can't remeber exacly from which chapter (3-6, 3-7 or 4-E-2)this was taken from.
I am almost positive that it will allow it. I will have to check. :S Another thing on the list. If not that, I could hack in statboosters. :/