Agreed, their software stack needs work, but thankfully that's why they are sponsoring developer events like you attended. The progress is happening fast and this is something that wasn't happening at all 6-12 months ago. It is a real shift in focus.
If you have specific areas you'd like me to pass up the chain for them in order for you to build support for your engine, please let me know and I'm happy to try to help however I can. It took a while for us to get there, but they are now extremely responsive to us.