Upgrades so far:-Dragon Hotend -Z-belt synchronisation ( https://www.prusaprinters.org/prints/149446-proforge-3-z-axis-synchronisation )-Insulation pad for the bed (you can get them for like 10 bucks on Amazon)
Z-Sync is awesome! Now also the Bed stays in place 🥳
Edit: added the download link
not particularly an upgrade, but the 5€ IKEA Lack table fits the Proforge perfectly and there are also nice things to print for it, like those organziers ^^