File size is bitrate times duration: there is no other lever. Flippy converts your 50 MB budget into kilobits, takes 6% off the top for container overhead, hands 96 kbps to the audio, and gives the video stream every kilobit that remains.
A 50 MB budget buys about six minutes of decent-looking 720p video, which is why it is the comfortable choice for tutorials and screen recordings headed to chat apps and CMSs.
The fix for a long clip is length, not settings: trim to the part that matters, then compress. Sixty good-looking seconds beat five minutes of mush every time.