I learned about the VCP mod after I had already had the car mostly assembled and it would have been a huge pain to get access to that part. I ended up doing something like what you're doing there, I alternated lifting the front and rear ~4ft or so and even after that there were still some bubbles. I ended up having to slightly pressurize the system and crack the top engine line and let the air escape. Not the most elegant solution but it worked and I've been driving it a while now with no overheating issues.