CEF Forum

The v8 users group is likely a better place to ask.

https://groups.google.com/g/v8-users

After further research, it definitely turned out to be a limitation of the V8 pointer compression.

I was able to rebuild Cef 90 with the V8 pointer compression turned off (by commenting out the setting of the V8_COMPRESS_POINTERS flag in the file chromium_git\chromium\src\v8\BUILD.gn)

This way, the browser processes consume much more memory to load the pages, but the hard limit of 4GB JavaScript heap space is gone, and if the machine has 32GB or more RAM, it can load the large and complex pages.