Well, my one problem with doing it the other way, is that most dado's I see only go up to 13/16ths, so they won't cut a 7/8th's.
The Freud 8" goes up to 7/8th with the shims.
You can see the board that clamps down on the piece being cut, on the other side there's some wingnuts I just have to turn each of the 4 twice and it locks in the pieces so tight a sledge hammer couldn't budge them. Also, there's enough room up front to cut two at once. (the board that's in there now, is just a test piece of wood by the way)
That will surely hold it, but I think it will be a pain in the butt and very time consuming. Even if you go for 7 dadoes and can do 2 boards at a time, your looking at 56 wing nuts per box
Here's the best part of my setup... I put these railings on the bottom to fit into the mitre slots on the table, so they let me slide it forward and back without ever having to worry about getting a diagonal cut like you do if you're just holding to the mitre thing.
All the jigs I have seen use this method, it works well as long as your mitre slots are true.
I can't tell by the photos, but I assume the pin is changeable for different size dadoes? Do you have any micro adjustment of the pin?
Here are some photos of mine. (Had to blow the dust off of it since I don't remember the last time I used it
Front side with replaceable backing insert
Micro adjustment of pin
Pins for different sized dadoes
I don't use mine anymore because I've found that the locking mitre holds up better as there is no end grains exposed and is less time consuming to do.
And the half blind dove tail holds up just as good as is super quick to do (only 4 passes per box)