The Cube 3 was a good little printer, but it was discontinued several years ago and hasn’t been supported since.
I don’t have my Cube 3 anymore (I currently have a Prusa MK2.5s) but when I did, I made several upgrades for it. Most of the upgrades were to be able to use 3rd party filament, saving a ton of money.
The main upgrade can be found here: PrusaPrinters
If you go to my prints, you will see other upgrades for the Cube 3.