I have a private 1.7.10 pack and I noticed that when moving the camera around, there seems to be screen tearing/the game seems to run at lower fps than the fps counter says. I couldn't resolve the issue for some time but then I decided to turn off borderless fullscreen in lwjgl3ify settings and the issue went away. Not sure if this can be captured on video.

After trying newer versions of Minecraft with other borderless fullscreen mods, I found out it was actually caused by an issue with AMD drivers (probably 24.6.1+ as 24.5.1 works fine), not LWJGL3ify.