simpler at this point to use the case_fold function of Unicode::CaseFold in both cases

Sure, TIMTOWTDI :-) Personally I just prefer core Perl when reasonably possible.

Here's another variant (Unicode::Collate has been in the core since 5.8), although the sorting order is different:

use Unicode::Collate;
@list = Unicode::Collate->new()->sort(@list);
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