I can not see the videos in short courses. Looks like they are encoded using H.264, which requires paying royalties in certain cases. And my Linux distro uses only Open Source software.
Is it possible to (additionally) encode the videos in VP9 or AV1? Firefox and Chrome already support AV1. AV1 provides more bandwidth efficiency - less space/traffic for the same or better video quality.
I can modify the course platform pipeline to support AV1 given you are interested in making the platform accessible to a broader range of users.