I actually posted my reply before I was finished... so the rockboxed fuze really wasn't working anymore so I thought if i reset it to factory defaults maybe it would, but I couldn't do it because the sandisk app on windows didn't recognize the device, so I tried formatting it and it was the final blow: now neither OSes (linux/windows) recognized the device and I couldn't really do anything else with it. Not even use it as a flashlight because pushing the power button didn't do anything. Too bad cause it would have made an ok flashlight.
What I didn't like with rockbox is that it felt limited, there were some basic features I needed to be able to use, like changing the volume without being in the "now playing" display, remembering FM stations presets, etc. It was fine for 90% of the expected behavior but there was always some really annoying lack. I do salute the effort of rockbox developers, they're making a really relevant product, and I myself will also encourage anyone who's not satisfied with their firmware to try it, it's just that the Fuze+ version wasn't fine-tuned enough for my needs at the time.