>> This feature should be opt-in, not opt-out, IMHO.
>
> No, let's enable it in environments where it seems to work. 

Yes, please.

>> Please consider also changing the option values so that
>> you can use `M-x set-variable` in a reasonable way (i.e.,
>> without needing to know that ?` is 96 etc. - you cannot
>> type ?` at the prompt).  Character values are not helpful
>> in such a context.
>
>
> Alan made a similar suggestion a while ago, and it's easy enough to implement. Done in the attached patch, which I pushed just now.

The options look good.
Did I misread the patch, or is there no value for "just display the quote verbatim, never translating"?