I've previously mentioned the problem of adjectives and verbs ending in 'c'. If you want to add 'ed' or 'ing' to 'panic' or picnic', you need an extra 'k', so we get 'panicked' and 'picnicking'.
But what about words like 'chic'? What is its comparative form (meaning "more chic")? If you write 'chicer', it looks like the 'c' is pronounced as [s]; but 'chicker' is no good. So it is basically not possible to write the comparative of 'chic', even though the word can be said.
And if 'to mic' is a verb (meaning "to put a microphone on someone"), what is its progressive form? If someone is doing it to you, are they 'micing' you? Or maybe 'micking' you? Neither one works.
I just saw another example of this in a BBC report of a football game between Wales and Moldova. If 'arc' is a verb (meaning "to move in an arc"), what is its progressive form (or, in this case, its derived adjective)?
The BBC used 'arcing', but that does not work for me, as 'c' followed by 'i' must be pronounced as [s], not [k]. But what alternative is there? It seems that 'arcking' isn't quite right.
So there doesn't seem to be an easy solution. I guess the rule that 'c' followed by 'e' or 'i' is always pronounced as [s] now has a few exceptions.