I don’t know how if this is the intended behavior, but when enabled all video posts are still there when scrolling the front page, the videos are just not playing anymore.
It's currently not possible to completely disable videos. This is why it's labeled as a beta feature.
Instagram's code uses the Observer API to fetch new posts when scrolling. If videos are entirely hidden, this functionality stops working. Additionally, Instagram relies on a secret hash for each fetch request, making it nearly impossible to modify or bypass.
