[Plugin: W3 Total Cache] Trailing slash in permalinks and disk cache mode

Why exactly the developer version of W3TC insists on a trailing slash in a permalink structure when I choose a disk enhanced caching mode?

Search engines already have a lot of my site’s pages in their base and /page is not the same as /page/. New pages (with trailing slash) will be considered as a dublicates and this is not good I think.

Is it possible to use an encanced disk caching mode and have a permalink structure like /%category%/%postname% but not /%category%/%postname%/?