EFI booth path isn't standard (EFI installation in Virtualbox works fine, but upon reboot it loses its NVRAM and isn't able to find the EFI boot files)
[Fixed in git] squary window borders on tiled/snapped windows
Clock says 15:38. Go to time settings. Turn off network time. Turn it back on. Wait for 10 seconds or so.. time updates to correct time and says 16:38. (either Cinnamon loses track of ntp when disconnected/reconnected to network, or it fails to use it at login time)
gksu covers cinnamon panel and clutter layer (offending code is in libgksu, won't fix, likely to migrate to pkexec instead)
GTK dialogs use symbolic icons (offending code is in GTK, won't fix. Small issue but linked to GTK3 becoming a GNOME Shell specific toolkit. Long run decision on whether to patch/freeze gtk or to migrate to a fork/alternative toolkit. No action taken in this cycle.)
Support for Wacom tablet (configurable via the command line, will need to join forces with Xfce/MATE if we want to develop a cross DE UI. This doesn't justify pulling resources to make a Cinnamon specific solution)