4GB is not a lot on Android so 10 tabs sounds about right. You need a lot of wiggle room for garbage collection to be efficient and you can't swap to flash without burning write cycles and power on small devices.

That aside, I don't see any technical reason why you can't renew a token that expired 1 week ago. Renewal just makes sure nothing changed (Eg user hasn't been deleted) while you were gone. It doesn't have to do any user-facing auth