We do our single engine approaches in config 3. For a SE go around we move one notch up, I.e., config2. The only time you use config full single engine is if you are doing an auto land in a 320. 321s and 319s can auto land config 3 or full.
Airbus SOPs call for Config Full landings preferred, but 3 is permissible. The only time I use config 3 in normal ops is if I have a long runway where I don't need to make an early turn off, or I have a possible windshear situation.
I have been flying pic on the 320 family for almost 20 years, with a 6 year break flying the 757.