It's verbose but will include the utf8 flag plus the dump showing the codepoints in hex. °

Which is more helpful for us than the OP's copy and paste.

> A decent print unpack 'H*',$data does the same with less fuss.

True, but unpack tells me "why" it went wrong? ;)

Update

> but displays as 'Kü',

Provided code areas in the monastery are encoded in utf8. I vividly remember problems here. *

*) the monastery is using windows-1252

°)

--- Testing: Täst:  "T\xE4st"
SV = PVMG(0x29c3c98) at 0x29c1fa8
  REFCNT = 1
  FLAGS = (SMG,POK,pIOK,pNOK,pPOK,UTF8)
  IV = 0
  NV = 0
  PV = 0x24c9c68 "T\303\244st"\0 [UTF8 "T\x{e4}st"]
  CUR = 5
  LEN = 10
  MAGIC = 0x2ab1b38
    MG_VIRTUAL = &PL_vtbl_utf8
    MG_TYPE = PERL_MAGIC_utf8(w)
    MG_LEN = 4