My Moto X Play (6.0.1, rooted, Xposed installed ) has dual SIM options, which I usually don't use. Recently, I had a need to use two SIMs, borrowed one with generous data allowance and second (personal ) SIM which was halfway to hitting the data cap.
My need was to configure data usage on a per app basis so that :
I don't exhaust data on my personal SIM while being able to use mobile number linked accounts like WhatsApp, Uber, banking accounts etc.
For all other apps , use the data from borrowed SIM
I couldn't find an app to do this, as is evident from this similar question, which has no responses yet -Is there a way on a DUAL SIM Android phone to configure on a per-app basis, which app uses which sim card to access internet?
How do I configure SIM data usage on per app basis ?
(This is a self answered question to share one way of doing it. You are welcome to post alternate solutions )