that´s by design: When in debug mode (web.config compilation debug=true), nothing is minified.
When you are in release mode, all embedded resources are minified and bundled.
Additionally Wisej “pre-minifies” and “pre-bundles” the resources into temp files so it does not have
to do it on each request. The temp files that are “pre-deflated” end in “z”.
That´s the maximum amount of optimization we could think of.
Find more information about Wisej minifaction here: http://wisej.com/docs/html/Minification.htm
Hope that helps.