Answer to the Q
hello skyhigh,
the answer to yr Q is Historical training record.
the ONLY reason BA dont take mod students is because in the 90's they took on a group of 'self improvers' aka mod students. They failed their training - didnt reach BAs standards; and cost BA alot of money.
hence they dont want to make same mistake again.
As to why these mod studes failed is an entirely different debate.