It was painted after it was installed. It came primed and they did not paint the cut edges. The pieces were butted together at installation and they caulked the joins, then painted. I don't think the installers had any problems while doing our house. Hardie products are very popular in my area - so most of them are familiar working with the concrete siding products. Nichi is a newer product in our area and I chose it after a designer I work with used it on a new build and felt it was a great alternative to Hardie. We are hoping to get 15 yrs on our paint job. I have a feeling we're being way too optimistic with that goal!

Yes. LP has bigger chunks of wood and generally the bigger the piece of wood, the slower the rot. In my casual observations of scrap left on bare ground, the Miratec deteriorates much faster. I think LP is using better, more rot resistant adhesives but have nothing to back that up. LP is closer akin to OSB and Miratec is closer to fiberboard/particle board. OSB is far more structural. I find this logic backed up by LP being more installer friendly(easier to handle longer pieces without breaking).

Their installation instructions say: Alternative Corner Treatments  Sierra Premium Shake and Smooth boards may also be installed with mitered corners. For best results, use a compound miter saw to accurately cut the 45 degree miter cut and slope angle.  Sierra Premium Shake and Smooth boards may also be installed in a laced or staggered corner application.  Nichiha recommends installing a galvanized, coated aluminum, or vinyl PVC flashing over the building corner prior to beginning a mitered or laced corner application.  Use a polyurethane adhesive where mitered or laced boards join. The only way to determine how to stain the cut edges is to get some shakes and experiment. Perhaps the manufacturer will send you some samples in the color you want or get an architect or builder to ask.

Owen, We are going with the Nichiha Sierra Premium Shake as well with our new build. We have heard only good things about the product. If you would like to see more samples, go to https://nichiha-samples.tbistores.com/. Nichiha sends you samples at no charge and they are nice sized samples. I also had alot of questions about the product and spoke with one of their reps and he was really informative and helpful. To get the variation in color like the photo you posted, I believe that would be factory finished by a company like Carolina Colortones. [This house[(https://www.houzz.com/photos/lakefront-residence-i-the-reserve-at-lake-keowee-traditional-exterior-phvw-vp~4502462) has a similar look to your picture and it was done by Carolina Colortones . We are wanting a stained cedar shake look and are planning to order through Custom Home Specialists in SC. They are less than a mile than where we are building so it works out. They have the same type of equipment that Carolina Colortones uses and can apply a stain to the primed fiber cement board. I looked into ordering the Sierra Premium Shake in Hazelnut or Terra but found it was way more expensive to do that than to order through a company like Carolina Colortones and have a custom color applied. I don't know if where you live doing something like this would be cost effective. I have also noticed the factory finish shine you mention and have heard this fades over time.