hey bruno, it's great news that there will finally be an update.
midi local on/off is definitely needed!
also, trigger the arp via analog gate-input (like on the microbrute) would be most welcome.
and when you work on it, please also consider this:
if possible at all, please by all means do implement a 'system settings' mode where you can set things like 'local on/off' or 'env retrigger on/off' on the device itself instead of having to use a pc!
ui-wise at least, that shouldn't be too hard to do: hold 'tap' button while powering on to enter 'system settings', then use keys to edit settings (c1 = local on, c#1 = local off, etc).
i really think you shouldn't need a pc to configure such basic settings on a kb synth. local on/off, env retrigger, and arp 'hold'/pseudo seq on/off are things that you want to toggle quite often, without having a pc around...
[edit:] oh, and i volunteer as a beta tester. i'm pretty good at finding bugs and quirks...