How to cache an encrypted stream for perfect playback?

So since there are streams that youtube-dl can't capture because they are encrypted however is there a way to setup something to ensure there's no drop outs/buffering/resolution change during streaming? Not sure if this would be a browser plugin or what, I did try increasing the cache size in firefox media.cache read ahead limit and resume threshold to 9999. But I noticed this doesn't seem to make a difference if you pause a video and watch the network tab in the developer tools. Everything seems to stop at the first segment. This would at least help if one wanted to screen capture and back up their purchased content that isn't available anywhere else.