As to this being a workaround, that’s all that can done. Either Arc gets turned into one of the less accurate, less detailed apps, or Apple make some fundamental changes in the way iOS handles long running background apps.
If Arc has to be tuned down to match those lesser apps, what’s the point? Just use one of those apps if that’s what you’re happy with.
You’re not going to get some other answer just by repeatedly pressing me on it. The facts remain unchanged.