I'll let others who have been in DYS for longer comment on what it has to offer. So far, we have really enjoyed learning from other parents who have BTDT.
There are definitely 2e DYS.
We didn't try the portfolio option (tests actually seemed easier to us), but I think you could submit "not accepted" but high test results as part of the portfolio. I'm not sure about Dibels though. I thought that was just reading speed and accuracy. Do you perhaps have some other testing?
Have you thought about letting your DC take the EXPLORE test? It is relatively inexpensive. It may be more challenging for your DS with processing concerns (because it is timed; does he qualify for accomodations?). DD9 qualified for DYS using EXPLORE, while DS6 qualified with the WIAT.
Best wishes whatever you decide!
