I am not sure whether the question is still actual, but in case someone else would like to switch between license server in SAP Business One Client, we have developed a small wrapper that will help you to do it.
Please try the free version of the application from our web site:
Skybuffer SBO LogonPad (version 0.2)
That's a kind of solution that is not recommended to be used in production environment, but could be very helpful and fast way to jump between different license servers for SAPB1 consultants.