The bottom line is that for your users the "documentation" that they will most often use is the existing contents of the configuration file. They should never need to see the Perl nor the module documentation to configure the system, so the issue of quoted / in the configuration file should never arrise.

A trick that you could use is to replace / with \ everywhere in your source, then normalise the paths by replacing / with \ at the "last minute". The configuration file isn't affected and you don't need to worry about quoting \ in your code (except in the normilisation routine). Note that a lot of modules are pretty blase about the difference between \ and / in files paths so normalising as a last step is often a good idea in any case.