Thanks for all the work here, OP. Though, I pretty quickly decided, since it'll be a long while before it affects any decisions, I may as well wait for more work from the production sensor matched with the production firmware before scrutinizing anything, myself, but i've been getting curious.
Going back a bit, someone mentioned trouble with the meter pattern selector getting moved around and not being noticed. I applied a simple solution to my K20d (Mostly, I had a tendency to just *forget* when I changed meter patterns, but I use a pretty fat neoprene strap which occasionally gets hold of that when going in or out of the bag.)
I just painted in a couple of the notches on the switch with white, which makes it a lot more noticeable from most angles, and found it really helpful, cause you can spot it from other angles. Here's a little bit of a pic:
https://www.pentaxforums.com/forums/572587-post17.html