This is nothing more then a nice to have.
Let's encrypt support baked into Kemp.
(Someone made a guide on how to integrate, but this requires an external server: https://blog.ganser.com/automate-lets-encrypt-certificate-renew-and-deployment-to-kemp-loadbalancer/ )
However this is not a perfect way to do it. Using DNS validation this could be made to work with Kemp.