I've been following the same threads as you, trying to work out which one will convince me to part with my cash.
I had been leaning towards the Onkyo, but this latest information does concern me.
Future development is an inherent aspect of the X7 and I expect this will cover firmware too, although updates may take some time to emerge.
Larger companies have a habit of killing projects, even relatively successful ones, if they don't deliver the bottom line profit expected, so I wouldn't make any assumptions about long term support for this DAP.
Irrespective of the audio performance I certainly won't touch the Onkyo until these significant UI issues have been addressed.