another idea is the testing: let Dorna organize the testing during the winter, and IMO 3 3-days tests are enough. So no expensive private sessions anymore, but teams only allowed to test on 3 occasions (there might even be spectators, when every team will come to the test sessions)

during the season, it is quit helpful to test the day after the GPs, so you only have to book your team members one night extra and you don't have to fly over the stuff you have to a test location