I don't think that's the best use of everyone's time or energy. Not to mention, it may be more error prone, or even insecure depending on what your base system is like. And you'll have to track updates. It seems like chromium is problematic to build in general. Debian hasn't marked it as reproducible. It is also not clear if it is possible to build it for Android using a Foss stack. Various efforts to include chromium or derivatives in Fdroid have failed.