I have a 4.x Pro license for ios and android.
Recently I have been using 5 Free and am thinking about upgrading…
My problem is that I have started using 3 machines…
iMac for the ios builds, my main desktop development PC, and a gaming PC Laptop for when I travel or am working remote.
I have Unity 5 Free on all machines and use git to sync between them
Everything is working great. 
If I start using Pro on 2 of the machines, will I be able to use Free on the project when working on the other machine?
Thanks for any clarification…