Hi Jussie, 
I believe this is the Certificates plugin from Moodle that makes the design of certificates easier to customise. From what I understand this certificate module is in use because the Certificate module in Totara Learn doesn't allow as much customisation as our customers need. 

You are correct, Totara Learn should have a better experience for our customers around creating certificates. We have in fact, done a review of this in the past and we estimated that it would take a couple of months at least to get the plugin refactored for production quality that would be suitable for integration into Totara core code. With the opportunity cost of this initiative so high, we've made the decision to put it on our backlog for now. The intention is to pick it up again in the future, but at this stage I can't commit to a release date. 

Thank for raising this and putting your voice into this discussion.