Just relegate your secret communication exclusively to secure E2EE communications such as Signal. If you don’t want your cell service provider to be able to identify you, use an anonymous payment method and provide a fake name if required. Keep your phone on airplane mode when at home, so your cell provider doesn’t learn your approximate home address. In general, don’t give info, or give false info.
Aurora isn’t any more of a man in the middle than Obtainium is. Aurora downloads directly from Google Play. Obtainium downloads directly from Github (and other sites).
As we’ve discussed here, Kagi doesn’t offer privacy benefits over free search engines like Brave and Duckduckgo.
I use Magic Earth. It’s proprietary, but its privacy policy seems decent.