When I submitted my first run for this game, I got a mod note telling me to please play in large screen and not small screen. Now that I actually have to try to get a PB, I think that playing in small screen should not only be allowed, but encouraged. While there are small mistakes and strategy improvements for this game, the biggest way to gain/lose time is the mouse movement in game. Ideally, you want to move the mouse the most distance as possible so that the knight moves less far (the cursor can travel faster than the knight). In order to go faster, you could up your mouse sensitivity, but that makes it very unnatural and difficult to control. A far better solution is to play in small screen. Since the game is smaller, you have to move your mouse much less to get the knight in the right position. Also, small screen also reduces lag (although this game very rarely lags for me). Playing small has a lot of advantages, so I think it should be the default for speedruns.
Edit: Also, when you reset the game on eddynardo.com, the default size is small not large, so it saves a few seconds each time you reset too.
I had never thought of that - its a really good idea. I'll allow small screen now. My only concern is that some players might not be used to the small screen and might need practice with it.
I think that needing to practice a bit is worth the timesave; my biggest concern is that it looks ugly