I think that since your repeat is small, you will probably get more variety in your blocks if you go with the smaller block size that you started with. In my experience, large blocks start to lose their mirror image quality in a 4-patch.
You also get more variety if the repeat is NOT a multiple of the cutting size. For variety, you need each new cut to occur at a different spot in the repeat. For example, assume that one spot in the repeat is where a red flower's stem just touches the flower. If you always cut through that point as you're working your way across the fabric stack, then all those blocks will be identical. Generally that is not what you want in a kaleidoscope design.