Loathed to try and add something into the mobile templates as they're meant to stay light and clunky-free
You should still be able to add an attachment. Through the go advanced option. You might need to go over to the desktop skin to access that, but tbh if you're using a decent smartphone that would be far preferable to the mobile skin anyway? I'm with SM#16, the mobile skin should really be as basic & simple as possible for small screens and slow connections also peoples low low bandwidth caps don't get hammered with extra charges.
Definitely disagree, the mobile site is good enough but the desktop skin on my Galaxy S4 is unusable, so much zooming in and out.