I don't find it that hard to come up with cases where I'd want to look at the bytes used to represent some UTF-8 string. Probably these could be done by unsetting the UTF-8 bit on the string (or on a copy of it), but there being more than one way is Perlish.

For example, I might just want to know the storage size of a UTF-8 string. Perhaps I have an algorithm that compresses using the concepts of bytes but I want it to "just work" when given a string, whether it is UTF-8 or not. Perhaps I want to transmit a UTF-8 string over a system that has problems with some specific bytes and I want to check for those bytes. Perhaps I want to uuencode a UTF-8 string. Perhaps I need to compute a byte-based checksum of a UTF-8 string.

I certainly wouldn't rule it out: I can imagine there are times you'd want to peek at the internal encoding of a string. However the only reason I can think of off the top of my head is to investigate a problem that you think may be a bug in perl, and there are other hammers I'd usually grab first in such cases (such as Devel::Peek, perl -Dxxx and the hammer-of-hammers gdb).

Hugo