Yes, we run casting computer simulations as part of a daily routine. Been in production for 6 months - still fairly new and working out the bugs.
We perform leak tests as well, but we do not leak until machined(as you stated above). This is machined at our customer, therefore external scrap...
The application is high pressure die cast aluminum engine blocks. We perform x-ray checks on sections of the casting to check for gas and shrinkage porosity in critical leak path areas. A large effort is being placed into moving this porosity with parameters and design, but the cost involved...