That’s a fine way to submit the video. You may not even have to go through the trouble of editing a LiveSplit timer unless the game explicitly requires one in its rules. If the rules don’t say anything about needing a timer (usually you don’t unless the game has specific requirements) then you can just use the YouTube video to submit. You can always ask a mod of the game too if you want to double check about the timer, but most times having video is enough