Whenever I render a video with Replay Mod, it renders useless frames and becomes a hassle. If I'm recording something that is about 20 seconds, the output is 2 minutes. The first 1 minute and 40 seconds are just frozen frames of what I'm recording, and around every five seconds it will change. When I get to the last twenty seconds, the replay finally plays. How do I get rid of all the unnecessary rendering?
Time keyframes remember the current time in the replay when they are placed. Where on the bottom timeline they are placed determines when in the video they take effect. You probably positioned your first time keyframe on the bottom timeline at 1m40s which is why it only applies at 1m40s into the video and nothing happens before that.