This came up in OpenFormula SC. In order for users to specify direct control over normalization we need a function like this:
Text NORMALIZE(Text input; Text form)
Returns the "input" string, normalized according to the Unicode normalization form specified by "form".
"form" must be one of "NFD", "NFC", "NFKD" or "NFKC", with semantics defined in [UniNorm]
[UniNorm] David, Mark and Martin Dürst, "Unicode Normalization Forms, Revision 25", The Unicode Consortium (2005)