Thanks for your reply!
I’ve been looking at AutomateWoo and trying to work it out if it’s functionality will do what I need.
It looks like the ‘Add Note to Order’ trigger could work for what I need, if I could add notes to bulk orders in one go, then send an email based on that – the note/email could simply let customers know the PDF/eBook has been updated, and to use their original download link to access it. The plug-in does have other features which I could use too, so it’d be fantastic if it could work this way.
For the eLearning side, my web dev has recommened LearnDash so we have that installed, so I think we’re covered, but I’ll check the others out as well.
Thanks for recommending something that was already on my radar, it’s reassuring to know I was looking in the right place!