For anyone on the dev platform , this is what I did on the Five Template.
I edited the main.nav block as followes, I can't remember exactly what I changed as I don't have the before and after but I think the bold text JSON may have been the only alteration. This will cause the folder link to automatically trigger the folder URL.
<a href="{collection.fullUrl}" {.if folderActive} class="active-folder"{.end}>{collection.navigationTitle}/
Whilst being exactly what we want for those with hover functionality, it's a problem if you're on a touch device . However I don't think