Hello StealthOz, first of all your girl is looking good.
To answer your question, i think its not that beneficial the way you put it down around the stem.
Main use of perlite is to mix it with the subrate of usage.
In your case coco, and only to make sure that there are airgaps in the substrate for better drainage.
My guess that your not transplanting this girl, maybe when you have a next grow you mix in the perlite with your coco to acheave that.
You can use different ratios of mix. I recommend atleast 30% perlite 70% coco.
I use a ratio of 60% coco 40% perlite myself and it works great.
Hope this was an helpfull answer my friend.
Keep on growing. Peace ๐๐พ