I'm concerned you are providing incorrect information regarding iOS updates. Or, perhaps, its a language barrier and I'm misinterpreting your append.
iOS App store CAN be configured to NOT automatically update iOS applications on your phone. In iOS App Store , if configured to NOT automatically update Apps, the configuration applies to ALL apps on you device. You can't configure it based on individual apps. While inconvenient, not a show stopper (and it would be Apple who would have to redesign the App store. Its not anything ZWO can work around unless they started recommending jailbreaking your iPhone).
In iOS , Settings->App Store->AUTOMATIC DOWNLOADS->App Updates (turn it off).
Once done, you can review the apps that have an update available by App Store->Upper Right Icon->Available Updates. You can then pick and choose which apps you want updated. This gives you the choice of NOT updating the Seestar App which then avoids the associated firmware update as well.
Apologies for the verboseness of this append, but could you please confirm ZWO support understands this?
Thanks.
P.S. 3.68 firmware works just fine for me.