I use Amcrest which does have their own cloud I don’t use but they also support ONVIF which is what you want. Then if you have a firewall with rules or piehole/adhome you can block their outbound if you want.

Agreed to the extent of short runs. All my pv lines are in conduit outside for protection kike most probably are and should be. My bat runs are short so no conduit. Longer runs that leave it exposed more should have the extra protection.