We are in the middle of a complete remodel of our house in Sonoma County, CA.  The exterior is being updated with Zip-R sheathing, new windows and doors, and Hardie Artisan Shiplap siding.  This siding uses a lock joint to allow for blind nailing and can be installed with mitered corners (which is what we have spec’d).  The siding is 10 1/4″ wide with a 9″ exposure.

Our builder does not have any previous experience with this specific type of Hardie siding, so I wanted to see if anyone has experience working with this product and has any advice or cautions.  
– Is the lock joint sufficient to keep the material flat, especially given the 9″ exposure?
– Any tips or tricks to achieving the mitered corners?
– What’s the best way to handle butt joints?

Thanks for any information