Ethyl Maltol is the candy floss smell in candy floss. It is slightly sweetening but its main use is a s a flavour enhancer - it can 'pop' some dull flavours into life. PA's sweetener is sucralose based and is just a errr sweetener. You can add either EM or sweetener at any point in a mix, but 2 things
a) Ethyl maltol will react with your juices and is best steeped
b) Add anything after your initial mix and you will dilute both the flavour and the nicotine content.