I've been wanting to migrate to FireFox for a while, and I began the process today. Progress halted fast, however, because the Firefox addon is incompatible with iPassword 4 and requires the subscription version instead.
I know that you offer the subscription model because it enables travel mode and other benefits like 2FA, but I'm perfectly happy with my onetime-purchase version, as money doesn't grow on trees.
I feel that an important feature like Native Messaging should be made available to iPassword 4 owners, so that people have a choice which model fits their feature list and wallet the best. There are probably third party addons for Firefox out there that has this feature, but that is defeating one of your design principles that you should never have to trust a third party with your password wallet (and trust them to not silently siphon all your logins), something I'd never install.
So in the spirit of your design documents I hereby sincerely request this feature to be added to the Firefox addon.
1Password Version: 188.8.131.526
Extension Version: 184.108.40.206
OS Version: Windows 10 1803 build 17134.81
Sync Type: Dropbox