One thing I have realized that my previous test where white layer wouldn't change anything for all modulo mode to verify that they all work as expected, I realize that at this point, modulo shift continuous just doesn't make sense from the functional point of view. To clarify, if you set 0 on the blend layer using modulo shift continuous, it assume that there's a shift because of inversion. However, 0 shift is 0 shift as in there shouldn't be any changes. So, this patch fix the functional point of view.