I believe the Open mode in Form printers disable couples of interesting features that don't seem strongly connected to material properties of resin used, like resin recovery to tank and vat stirring wiper.

Form resin vats/tanks/tray/bed/whatever you call it are also not just proprietary, but their equivalent of FEP film is not replaceable. The resin vat usually have what is referred to as FEP film, a thin transparent Teflon sheet at the bottom of about a phone screen protector thickness and durability, stretched and pre-tensioned like a drum. The non-adhesion performance of film affects print quality, and it needs replacement eventually(I believe it is characterized as after x thousand layers printed, internally by printer manufacturers). On most printers, the replacement film can be bought and installed by the user. Formlabs printers use something other than regular FEP, and uses tool-less assembly that cannot be reversed, and therefore the whole proprietary tank needs to be discarded and replaced.

It's like Bambu Lab but the printbed is proprietary too and heated bed turns off for non-Bambu filaments. As if proprietary nozzles was not enough.