Default two whatsapp running at the same phone

Back when the whatsapp beta was public I had both versions running on my phone. I wonder if it would be possible to save the XAP in an interop ulock ATIV S for installation on a developer phone unlock and have two whatsapp running at the same time with two different numbers. Then we could have two whatsapp even when the phone is restored. The current whatsapp beta is restricted, but surely there are still people that preserves the previous version