Fabio Manganiello (npub13uu…pvgs) Firefox is a web browser, not a browser engine. Its browser engine is Gecko, or it will be after iOS allows other engines, but iOS will not have access to Gecko outside of Firefox. Hence, rendering PWAs in other engines requires opening in other browsers.
By contrast, WebKit is built into iOS, not Safari. That’s been true from day one. Third-party app support arrived later. iOS never had the architecture to access browser engines in third-party apps.