Get new RAM modules: 2x32GB DDR4 SODIMM.
Now I can run 8 VMs and 2 IDEAs at the same time, meanwhile having infinite chrome tabs opened.
Here is a test screenshot, where I ran 8 VMs and 2 IDEA, one is running a springboot application service in the background. I also have a Minecraft 1.18 running. For the last 21GB of memory, I used it in the MemTest64.
I don't know why the system has a blue screen because of the "video scheduler internal error". But after I switch to dedicate GPU and switch it back, it just stops crashing.