Writing lessons as blog posts + quizzes seems to be the way to go for now. Later these lessons can be arranged into Namaste lessons if need be.
There are a few handy ways to structure a course out of the disparate lessons. One is to make the availability of a quiz depend on completing earlier quizzes, then a certificate can be applied to the successful completion of the last quiz.
The badges facility from the Play plugin can give a badge for completing all the quizzes in a certain section to a certain level.
Here is a list of all the quizzes right now: