I tried pulling the video from the Safari web client as it gave a giant data: uri in the <video> element that I thought I could save but couldn't figure it out.
Adding video support is rather easy, it is just something I never felt the need to do given my preference for audio - which I can listen to while working on the farm etc. - over video. I can have a look at adding it if there is enough demand.
I had a look at including video and it turns out I was premature in saying it would be easy. Currently librespot-python does not support video so only for that reason it is a no-go. If support ever arrives it might become possible but given that Spotify-video is burdened with Widevine DRM it might mean Spodcast would need to integrate a (headless) browser in the process to decrypt the video. So, for now, no video. For the future, maybe but don't hold your breath.