Sram and shimano Cassette

Hi there! 

I would like to know your opinion! My girlfriend and I we are sharing the Tacx Neo 2. And we have the following issue, she has an Ultegra 11 Speed drivetrain and I have a 12 Speed Sram drivetrain. 

What is the best or easiest way to share the trainer? Uninstall the casette and remove the freehub almost every second day is annoying. 

Any ideas? 

Thanks