Implementation details is not a feature and this is not a feature request in my opinion.
If you understand how mojoPortal works, you will know that all the pages in the menu aka CMS pages are served by a single physical page /Default.aspx?pageid=x so there is not a separate physical page for each page in a site. Page Methods must be implemented within the page so this would require Default.aspx to have page methods inside it to support every feature or it would require having separate physical .aspx files for each page. Page Methods can be used in supporting pages of custom features because those are actual physical .aspx files. I certainly don't agree with any suggestion that all use of postback should be replaced by page methods.