WooSidebars to add as well as replace.
WooSidebars is great. Sometimes I just need to add a widget for certain pages. So instead of replicating the entire rosta of widgets assigned to primary. Perhaps it would be better to have the ability to have the new widget just add the additional widgets and not replace.
For instance. I could have a new widget area called WooCommerce. Then set the parameters so when I am on a WooCommerce page (product page, category page etc..) It adds the widgets from this widget area in addition to the primary widgets. These widgets would probably be the cart widget etc..
Tom Hodgson commented
Or you could just look at another plugin which offers conditional widgets - I have found this one and I am going to try it http://wordpress.org/plugins/conditional-widgets