You can expand mirrored vedev based arrays, but you do it by adding vdevs, so you are looking at adding TWO drives at a time. You can also (sorta) expand Z1 arrays by adding whole additional vdevs, or by replacing each drive in the array one at a time.

Stop doing rhat.

Sigh and move on. Lesson learned.

A keyword pocketwatch built in 1886.

That camera has a sync speed of 1/250th of a second. You can use HighSpeed Sync (HSS) to go faster, but it makes your flash less and less powerful in effect as you go faster.