- Edited
Hi there, and thanks for your insightful and detailed post.
In time, you might very well get a more detailed response here from another moderator, but I just want to say that the GrapheneOS development team is not particularly active on this forum. This forum is more orientated around the user base.
Most of the development work goes on on GitHub, and you can absolutely find the developers there: https://github.com/GrapheneOS.
But as it seems you are looking to discuss this directly with the GrapheneOS project itself, I would suggest either an email to the project https://grapheneos.org/contact#contacting-the-project, or raising it in the development chatroom accessible over Matrix/Discord/Telegram: https://grapheneos.org/contact#community-chat.
You mentioned that you are looking to support the app development at GrapheneOS. Are you interested to work for them? If so, you might care to look at the hiring page of the GrapheneOS website: https://grapheneos.org/hiring, to see what the expectations would be.
Note that this information is provided in my capacity as a moderator of the GrapheneOS community (forum and chatrooms): I do that as a volunteer, and opinions are my own.