Unless you're shooting for a very long time, I use all-i over ipb for smooth editing. By the way, I'm testing this Vegas Pro 19 build532, and when I import the canon 4k all-i, the playback is choppy and choppy. And the black screen comes and goes again and again, but Vegas Pro Playback is very smooth at 18. Am I the only one having problems with Vegas Pro 19? Drivers such as graphics drivers are already up to date. I uploaded a test clip. Do you have a friend who can make sure you are playing well in your environment?
https://drive.google.com/file/d/1p82gXHpjwBM_yDUSc7N9pMbi6EFWRkp4/view?usp=sharing