That should certainly help, but may have been better if they were made longer (about 2X). I have no idea how your planer is designed, so I can't comment on how well it will work with these. Keeping the work flat as it goes through the planer definitely helps reduce snipe. However, if the head of the planer doesn't lock in place after it is adjusted, the movement of the leading and trailing ends of the board will still get some snipe. The snipe occurs when the feed rollers ahead of and to the rear of the planer knives rise onto and drop off of the ends of the board. When this happens, the planer head will tilt slightly and the knives will cut deeper than they do when both drive rollers are on the board. Some lunch box planers have no head locks or very poor head locks and snipe can be as much as 1/4". My first lunch box planer had very bad snipe. To minimize this I got into the habit of placing pieces of scrap material the same thickness as the work into the planer just before beginning to feed the good piece through and just before the trailing end of the good piece went through. This caused the snipe to occur on the scrap material and not on the good piece. If you still get snipe you may want to try this.
My present lunch box planer is a DeWalt 735. Even though it is a good design and the head locks in place, it still gets some snipe, but the snipe is so slight that it almost isn't noticeable. A couple of swipes with 100 grit sandpaper will remove the line, It's that small. Whenever I absolutely don't want any snipe I still fall back on my old method of feeding scrap just before starting to feed the good board and just before the end of the good board. In 30 years it has been the only certain way that I've found to completely eliminate snipe from my good boards.
Central North Carolina