Jay, I've tried 64bit beta with stellarmate. It works better than 32b astroberry but sometimes kstars crashes when FITsViewer is enabled and 61mpx ccd connected.
And SM cannot connect my second cam - RisingCam IMX571C with touptek driver... Don't know why as astroberry works good with this cam.
I'm not very good at Linux to upgrade Astroberry to beta:)
I am using 64gb card with os and 128gb as external usb3 flash card for lights and connect via VNC.
I do not complain about performance, but stability leaves much to be desired.