Flow is just a VEP and a Cubase file, it does not require you to do anything else than keep on using those programs like with any other project
It seems to me a performance issue with Cubase, can you check the performance meter in Cubase and see where it is?
Flow for Cubase has more than 1000 tracks and is connected to lot of Vienna instances, therefore this might be the problem, however so far no user has encountered such low performances
I suggest you to do the following things:
- Shut down all the vienna instances in Cubase, which you do by clicking on the power button of each rack and track instrument on the rack panel on the right. At this stage you should already see quite some improvements and so you enable only a rack if you really need it
- As a second option you can tailor down the vienna and cubase project to have less tracks and libraries, maybe only the ones you own
For the second point I can help you, if you purchase a 30 minutes support product and you give me a list of libraries I can do the tailoring for you, or you can perfectly do it yourself looking at the documentation on how to remove libraries for Flow (which lot of users have done themselves)
Let me know