Sounds hinky, I made about a half dozen offers on bank owned in the last year and they always wanted 3k that was conditionally non refundable. In each case, the only way they kept the money was if i got cold feet, all other situations I would be refunded and was refunded a few times (usually because I was outbid). In one case, the property wasn’t unoccupied yet, current occupant stripped the place before leaving and while i was in escrow, that got me out of the deal and my deposit back (10k worth of plantation shutters, light fixtures, appliances, etc.) I wanted a new price, they said no, i said FU, they gave me back my money.
I don’t think I’d sign a completely unconditional deposit, what if it burns down before escrow closes? You can’t insure it until it closes, that would cause you to eat the deposit, that blows.