Doing notes are great supplements when you're learning the content, at least thats how I feel, when I have a page which I am trying to essentially create an effective and efficient cheat sheet, it forces me to identify the aspects of topics that are not as memorable in the long run as opposed to aspects which I can easily recognise, for example in Financial Markets, I wouldn't consider knowing the definitions of shareholder or say investor as worthy as knowing how the Corridor System works and its effects. This would make me actively engaged in the content as opposed to just writing down lines and paragraphs subconsciously - again this is just for me, I'm sure people would disagree.
In that light, they are only supplements and it's a far stretch to claim notes are a strong component of exam-prep; personally they just cover the material I know I'll forget in some weeks. Try creating notes alongside learning eco in the future and see how that goes, I feel this is the most content heavy subject so far; equivalent to business studies. For now, if you do need notes, just get them off the economics notes and resources in the site and you can casually skim over it.
As of now, just do as much practice papers for eco as you can and don't worry about getting marks - the parts you struggle on will indicate the areas you need to revise for e.g getting confused with demand shifters -> revise markets and shifters. In this way, you can just focus on patching up your weaknesses rather than spending too much time on just eco, assuming you're aiming to be as efficient as possible.