If you are having trouble removing the support material (or rafts) from your 3D prints, the plastic may be getting too hot while printing.
On both the UP! Box+ and the UP! Mini 2 there is a vent on the extruder, which can blow cold air onto the nozzle during a print. This cools the plastic a little quicker and it won't stick as much.
NOTE: opening the vent may cause warping. If this happens, close the vent half way.
UP! Mini 2 Vent Operation
If you would like to open the vent, simply locate the handle on the left hand side of the extruder as shown below, and gently, but firmly push it towards the back of the printer.