Dual SIM device : How to configure data usage on per app basis (Rooted device)
Requires Rooted Device, Xposed framework installed,  latest version of GravityBox Xposed module and an automation app - I use Macrodroid

Create a macro in Macrodroid

Trigger: 


Application Launched &rarr; select from the drop down list, all apps you want to use on SIM card linked to banking, WhatsApp, Uber etc (5 apps in example below )
Application Launched &rarr; select from the drop down list, all apps you want to use on second SIM card (16 apps in example below )


( Make sure that apps don't appear on both lists !)

Actions:


If &rarr; +  &rarr; Trigger Fired  &rarr;
Application Launched 5 apps 
&rarr;
Tap End If and add this action - Launch Shortcut  &rarr; GravityBox actions  &rarr; SIM settings  &rarr;  SIM 1 for data 


Repeat this for second set of apps and choose SIM 2 for data

Constraints:   Leave blank

Done !