Custom running workout in Zwift

It’s been said before, several times, but no progress. Please allow us to create a running workout within Zwift, i.e., not having to create it in a third party and export it to Zwift. I just can’t see how it’s that difficult when it already exists for riding. Can work out details as you go such as what parameters are allowed and customizable, but to not even have it as an option seems silly.