So basically it is the problem with CFG (exploit protection) which is not ready for the cases when there are many allocations and freeing of excutable memory blocks.
Kinda; mainly that NtQueryVirtualMemory was super slow when scanning over CFG, which was bug fixed in the April 2018 Windows 10 update. It also uncovered a "bug" (performance weakness?) in v8 that they were able to fix so less CFG blocks were allocated. So kind of a win/win in the end, bugs fixed, world a slightly better place.
They implemented a freelist, it's a common workaround for problematic allocators, but has its own issues (https://www.tedunangst.com/flak/post/analysis-of-openssl-fre...)