Maybe we need another PEP that switches the default to WTF-8 [0] aka UTF-8 but let's ignore that a chunk of code points was reserved as surrogates and just encode them like any other code point.

[0] https://simonsapin.github.io/wtf-8/

My comment was completely unrelated to PEP 686. WTF-8 is emphatically not intended to be used as a file encoding.