How could I test my quotedetail plugin with the Plugin Registration Tool as there is no "New" button

I try to attach the debugger with the ErrorDetails from the profiler, however, it seems to only work with creating normal entity like opportunity and quote.  Since quotedetail or quoteproduct is a reference to quote, I don't know how to set up to allow it to be attached in the Plugin Registration Tool.  Any one have similar experience that can debug at creation using the quote line sub grid?