[Ola C]

I checked your description in the link and have a few questions. How do you ensure the template/slot is parallell to your workpiece? Is there some center marking in the template showing the centre of the cut in that direction? I also wonder about the idea with different templates. Wouldn't it work to just run it with router bits matching the dominos (5,6,8,10) mm and never change the template?

 

[Ola C]

You could scribe lines on the bottom side of the top, this should minimize sight alignment issues. I would make a line for the center of the slot and then several lines where the fence should be located. Checking the screw slots distance seems like a quite inaccurate method.(?)

Regarding the router bits I see your point, although I think having appropriate router bits and only one template would be a neater solution.