@fdroidorg We did not leave the F-Droid Reproducible Builds project, because we never entered it in the first place. It was not an active decision by us; F-Droid manages their own app repository and decides which apps go in and how they are built. Our development process results in two artifacts, a AAB build for the Play Store, and an APK build that is published on GitHub, both of which are made from the same 100% open-source, GPL code.
@fdroidorg F-Droid representatives asked us to start maintaining yet another build specifically for them; this was not communicated to us as an advance requirement for being on the F-Droid repository. Since the majority of our users are not on F-Droid, and our means are limited, we did not wish to spend engineer time on this, but F-Droid maintainers can maintain such a build on their own.