VRay 3.6 and Next on same workstation?

V-Ray V-Ray for 3ds Max General
1

I recently upgraded to Next 1.1, but have a client who is insisting on 3.6 files. Since I own an active license for each, is there a way to have both loaded in the Render Setup so I can choose between the two, depending on the client?

Thank You.

2

This is what Vlado answered me:

3

We use 3.6 on maya2018
and if its ready Next on maya2019

That worked in the past.