I had to look up the kit instructions about adding the priming sugar at the end of the boil. Something seemed wrong. Priming sugar is added to the bottling bucket for natural carbonation.
Instructions should say, “add five ounces of corn sugar, or add the included packet of sugar”.
I would start any one gallon brew in a one gallon fermentor with the blow off tube installed. The fermentor lacks the headspace for the krausen of any style beer.
Control the fermentation temperature. The warmer the fermentation the more active the yeast will be and the yeast produces more heat as activity increases. A swamp cooler is very easy to set up and effective to control the fermentation temperature in a small batch brew.