Do what I do.. make a batch big enough that it doesn't matter that you plan to leave it a month but start vaping it after ten minutes. Then make another even more massive batch two weeks later when you realise you are running out!
Why heat in a saucepan? Cant see how that would help really
... may mix the flavours into the base but may also completely destroy them.. make them harsher etc... they are not designed to be cooked..