The only slider I woukd think that would be affecting #1 WRs not being targeted is the cpu qb accuracy. Like I stated many times this dictates their awareness and they will only make certain throws the lower it is, so if you think about it the #1 WR is always covered by a good #1 CB and sometimes double teamed, why woukd the qb want to force a throw to him if he's smothered when the cpu qb accuracy slider is lowered. I honestly haven't came across this problem using cpu qb accuracy between 30-40.