I have brewed this kit a few times with good results. My latest had the 1.7kg kit, 1kg LME, 1kg sugar mix (500g dextrose, 250g DME and 250g maltodextrine).
I did a 20 min hops boil in about half the bag of sugar mix. 15g cascade at 20 min and 15g at flame out. The LME, rest of sugar and kit...