Sad to see the author (M66B) seem to be defeated by hard life, review pressure and Google policies.
I've been using the app for a few years, admiring its design and philosophy, and contributing its localization, as well as some communication to M66B. In my opinion, the project is amazing, but its development and community maintenance may not be so healthy. While M66B provides as exhaustive FAQs as possible, there doesn't seem to be an active, searchable user discussion community, and users sometimes have to ask the author directly - the author respond quickly, M66B maybe ever enjoy the process, but obviously it also brings great pressure. Even, I first noticed this amazing XDA post, and it doesn't seem to be included anywhere in this project. This also prevented me from sharing opinions or insights about the software, so I was always a user rather than a participant.
In fact, I've also tried reading and refining some code in small amounts and providing it to the author, but the private email exchanges and comments seem less efficient and transparent. This is still a one-person project, although it's open-source code. Other posts have made some suggestions for code structure / community, I hope M66B or anyone can pick it up.
Furthermore, I suggest M66B ignore flippant Play Store reviews as they may not be a user who actually needs it. And build a user community for user support, only provide limited personal support to protect your live. Google Play may be an important source of installation, but for privacy-oriented / loyal users, the third-party sources (GitHub/F-droid/...) may be better or acceptable.
Anyway, thank you for bringing this wonderful software.