I haven't done any research yet on your question, but I did hear the news blurb about National tightening of lending rules. In answering another question (link below) , I think I understand a little better why CA is proposing the creative financing disclosure. I'll also borrow from another person's answer that I can't find to give them the proper credit or exact wording. I believe they quoted a NAR survey that said CLOSING is the most important factor, NOT price.
In CA, the financing contingency usually isn't lifted until after closing. I have decided that is is a hostage negotiation.
Let's say someone uses an incentive of "zero percent interest for the life of the loan." This incentive would dramatically change to TRUE value of the purchase price. But if a bank is willing to lend me money for the true value of the home and I get creative to come up with my down payment via legal means, whose business is it other than the lender?
That's my 2 cents.