Multiple instances of your app, using TurboFloat, can be started and use the same license lease, however they all must be in the same desktop session (or terminal server session).
I was expecting only the first instance to run while all other attempts would give an error.
If you log into another user on the computer (thus another session) then you would get an error (presuming the TFS has no more "free leases" to dole out).
Does that make sense?