Deemed as optional is a synomim for dropped to any compiler that is yet to fully implement them, as they aren't required to support it for ISO C certification.
Several commercial compilers for embedded development, mainframes and surviving UNIXes, VC2019 since 16.8.
Additionally ICC apparently never supported VLAs that well.
> with clang and gcc probably being the only C compilers on Earth that might still support it on C11 and C17 mode
Are there any other C11 compilers even?