These first years are ordered to the acquisition of the skills necessary for any further learning. At this stage the student should concentrate on learning to read well, and learning to write, both in terms of letter formation and power of expression. He should also spend time acquiring facility in addition and subtraction. If these skills are learned well, all the rest of his school time will be much more profitable and his education will be more complete.
As a parent and teacher the time spent with your child is valuable. If he does not learn to read in kindergarten or first grade, it won't finally make much difference in his life. But you should spend time reading to him during these formative years. The saint stories, the tales of noble actions performed by noble people, and the fairy tales, with their clear divisions between good and bad, will make a lifelong difference.
Most of all it (being enrolled in MODG) has helped me remain confident and at peace with my decision to home school. Even when things are falling apart around me, I can pull back to the basics of the syllabus and know that my kids are getting a great education.