I have used all of the above tricks to get close, especially hoping that the dimensions are nice numbers (this is where a set of calipers that will show you fractional inches can be handy as well). Taking a picture of the part and importing that onto your canvas in fusion can help sort things out, but often doesn’t help with accurate measurements.
If I were smart I would have taken these pictures and measurements last week before I mounted my HDZ :).
Just a little bit more about what I’m doing - I’m trying to design a different dust boot setup that doesn’t sacrifice any X travel with the HDZ and gets the hose supported closer to the rail to minimize any deflection it could cause.
It kind of surprises me the hole pattern isn’t published by Carbide3d. I’m not looking for any sort of “open hardware” or a full model, but when a company is built around people who tinker and mod, it’d sure be handy to have the basic interface documented to encourage more tinkering and modding.