I have found a cool lib that allow us to run two instances of an app. For example, you can run two instances of Instagram app with different login information. To understand clearly, let's take a look at this app as a good example: https://play.google.com/store/apps/details?id=com.cmcm.multiaccount
The github project hasn't been updated since 2017, looks like it's a commercial product only now.
It doesn't look like you 'integrate' it with your B4A App in any way. Any App, regardless of development package, should just run inside the virtual environment it provides - subject to any limitations of the VA.
I'm sure it's not the only market product that can do this.
(https://duckduckgo.com/?q=android+run+multiple+instances+of+same+app&t=newext&atb=v271-1&ia=web )
Perhaps the VirtualApp author can provide better advice?
MIUI has inbuilt 'dual apps' option and I use it for double Whatsapp with each phone number of my double sim phone. I also have PayTM etc. as duals.
So it is OS feature or launcher feature, maybe.