question

A sponsor will typically have their preferred lender list- which doesn't prevent you from using another lender not on the list , but if that lender ultimately declines to underwrite, then you will need to apply to one of the preferred lenders.

If your loan is going to be under $750k, I would recommend First Republic for this building . They are on the preferred lender list (last I was aware- which was over the winter)- and they offer CRA loans for primary residents in much of the neighborhood- which results in rates that are usually 40-60 basis points lower than a market rate loan. I am an agent that sells in the neighborhood- and I have done a lot of deals with First Republic because of this program. There are a few other banks that offer CRA loans- but for most of my clients- First Republic's has been the most attractive. They are a little slow to get back to you initially, but once in process they are very responsive.

Typically have a preferred lender list sure. But preferred lender has to function as a lender. If a lender as a broker was referred to you as a lender. you essentially can not fufil the contractual duty of either provide " preferred lender commitment " or "preferred lender declination" . Does that give the sponsor a reason to remove your contingency if require an actual lender ? or the contingency is actually a structured non-working term under such arrangement .

"lender act as broker"

These are questions you need to discuss with your real estate attorney. Agents are not permitted to give legal advice unless they are also an attorney.