Case insensitive exact location match?

[E.B.]

> > 2^4 = all 16 combinations. Hopefully the 'test' sting is only 4
> > characters
> > long...
> >
> > Case-insensitiveness is no-trivial check, and if needed PCRE are here
> > for
> > that through regex locations.
> > What is wrong with them already??
>
> At assembly level alot, +-20 bytes including an if or alot more when it has
> to go through pcre.

Exactly. PCRE engine adds overhead and is slower than just case
folding. 

PLUS the Nginx location directive adds more overhead I'd like to avoid
because of its processing order. I know the exact text of what I want to
match, so = is the best choice. But I can't control the case of what clients
use. 

But answers seem to indicate Nginx has no such feature.