Jamus - when I wanted to do a temporary height modification to the blind on my DB 15 I used PVC with emt inserted to give it strength. If you do a search you will see the pics. The final height from the top rail to the deck floor is 43 inches. We sit on fold up tri fold chairs I purchased at Dick's and they are roughly the same height as a milk crate with a cushion except these offer a back support.
Back to your question, I can only tell you that this year I plan on reconfiguring the blind modification and definitely make it lower. I found that crouching down was not a problem but the height caused more movement when we shouldered our guns. I will use grass and salt hay to make any height adjust might needed.
Hope this helps somewhat and good luck ...... Joe


Good Luck & Safe Hunting