It would, I think, be counter-productive to flame off at PalmOne. At risk of editorializing, I suspect the incompatabilities we're experiencing with the T5 highlight how they've fallen victim to the consequences of the decision to split Palm into two separate entities.
PalmSource can't afford to play favourites with Palm One lest they alienate their other customers, but Palm One can no longer guarantee that they'll have the operating system they need, as/when they need it. To make matters worse, there's the Garnet/Cobalt fiasco, which PalmSource are managing as badly as Apple managed the successor to System 7 back in the mid-to-late nineties. It feels as if PalmOS 5.x development and maintenance is adrift, while PalmOS 6.x hasn't arrived yet. And PalmOne are the victims of this disconnect.
If you do end up talking to someone at PalmOne about the incompatabilities, you might try to frame your issues in a positive light, and say you're concerned about software compatability and support for existing APIs. (And a published API for text input methods like Fitaly to plug into would be a nice suggestion, albeit one that probably only PalmSource can take on board.)