It won't matter what size your seam is if your pattern is relatively simple like a 9 patch, 4 patch or any other that has all square or rectangle pieces. As long as you sew a consistent seam, the pattern will turn out fine. Your result will just be a little smaller than one made with a 1/4 inch seam.
If you get into complicated patterns where you are going for a certain size triangle or odd angles, you will have a problem. If you are aren't into more complex patterns, your machine should serve you well.
Bkay