1. These are weird to handle because they basically depend on how many characters can an int encode, which is implementation-defined, so to use these well in a cross-platform environment you have to uh... constrast the number of characters with the size & alignment of an int

Multi-character literals are unreliable to encode into an int because these depend on the implementation-defined size of int to know how many characters you can encode into, which in my opinion, is horrible.

Also, multi-character literals are unnecessary, most codebases use wide, UTF-16 or UTF32 encodings to encode multi-character literals appropriately (yes, i know wchar_t is less than ideal, but lets ignore that for now).

I don't think this feature serves any purpose nowadays, and the few codebases that may still use it should remove its support and get into the more reliable approaches, so this feature can be deprecated once and for all.