it's not so much that it needs a controller remapping option, more so that it simply needs the two buttons remapped. on a diamond pattern setup, like what we have with the zero, the X/B buttons work better than B/A. This is because it is much easier to transfer our thumbs down to B than up to A.
does it do on-the-fly ips patching? with the amount of ips patches available for nes games, it would be nice to see this added. so far i have only found time to test pre-patched roms, and those are running great.