On the one hand, don't sweat it because it's just elementary. My sister homeschooled her kids in early elementary, spending only an hour or two a day and they ended up accelerated one or two years (either side of cut-off), graduating at 16. They returned to brick and mortar school between 4th and 6th grade and was mostly fine but with noticeable weaknesses in writing compared to their cohorts. On the other hand, I would really watch his curriculum from 6th grade onward as the demands in a decent public school ramps up quickly and you don't want him left behind.
Your DS is still young so the focus should be on remediating his disabilities. The curriculum you described screams accommodations, which is great if it keeps him happy, as long as they/you are remediating his dyslexia/dysgraphia at the same time. I am assuming that he turned 8 recently so is young for 3rd grade, but the curriculum would be somewhat lacking in the reading/writing areas even if he were a second grader. In our district, third graders routinely write multi-paragraphs essays and read/analyze literature (short stories, excerpts, books) as well as science and social studies selections. At the same time, the extras sound wonderful as well as the logic problems and science project. The math curriculum is a mixed bag: it is great that he is reading word problems and graphs and studying fractions but make sure he learns to create graphs as well; it is strange that he is doing so many addition/subtraction worksheets in 3rd grade; modern curriculum also includes a lot of elementary algebra (24 - ? = 17, etc.) and elementary geometry (area, perimeter, etc.).
At this age, I would not under-emphasize happy so notwithstanding the weak areas I mentioned, the school still sounds wonderful.
