I know it’s hard to find things scattered throughout the forum, but I believe the answers to your questions exist:
- Pre-release vs. production: “If you choose to receive a pre-release unit, it will remain our property. We might need to make changes or improvements. We will replace it later with the production unit you ordered.”
- From the same post, regarding work area: “To do: When the laser is moving at maximum speed, it needs room to slow down near the top, bottom, and both sides. We’ll be updating the software to compensate for that so it can give you more working space - up to 11.5” x 20.4" for slow movements like cuts; a little bit less for faster motions like engraves."
- Are they still working on features? “Software features yes; hardware features no.”](Dec 2016 Glowforge Q&A)
I haven’t seen anyone refer to there being a release candidate of either the hardware or the software.