Hi Burr, unfortunately the way that most of these calculations work it is not really possible to estimate beforehand how long they are going to take.
A lot of the calculations depend on the shapes of the objects involved, like when you do a boolean if the shapes intersect along a surface that has a lot of wiggly bumps in it, it will take longer to calculate that intersection in that area.
But there isn't any quick way to tell if the intersection is in a wiggly spot other than to actually intersect it.
Many of the mechanisms for calculating things are like this, where they start with a kind of rough answer and then keep on refining it until the answer is good enough. These mechanisms don't know how many steps it will take before hand, they keep going until the final answer is at a good enough level of accuracy.
It's not the same thing as something like a file download where you know you have x number of bytes and a y download speed, stuff like that can be estimated a lot better.
 Michael
