In 7.0.0.79, I was able to connect to my Meade LXD75, configure it with ASCOM as I did in SN 6.4.3, and operate the mount from Starry Night. Right click on an object and select slew to... works fine, as does Sync Gaze. What does not work in the beta version is the manual control. There was no response from manual controls regardless of settings. Manual control did work for my set-up in version 6.4.3 (and still does; I just tested it).
I'm on a PC, Vista 32 bit with a prolific brand usb to serial adapter.
I'll put a bug report in, but perhaps others using Autostar mounts may have some insights.
Wayne