A lot of the seller in Alibaba are just buying camera OEM from a factory so they wouldn't be able to get you the software. The factory itself might be just copy

A lot of the seller in Alibaba are just buying camera OEM from a factory so they wouldn't be able to get you the software. The factory itself might be just copying the reference design from chip manufacturer and they might not have access to the code or under a NDA. The chip manufacturer does not have an incentive to provide you custom firmware. You aren't their customer.