The insurance companies so far were accepting multiple camera brands if part of a professionally installed and monitored service like ADT or Crestron.
But for self installed systems, they wanted the camera to be part of the branded package before they gave the discount. They don’t want to Individually evaluate each homeowner’s set up (too costly), they want to approve the system. hence Iris and Simplisafe, yes, Staples Connect and ST, no, last time I checked.
But every company has their own rules, which also vary by state.