You could've edited one of the new comments instead of adding 2 more
No treasure chests are missable except the possiblility of the 4 at the start. My guess is that they
don't count because when you open the map, the icons don't show at the top-left, y'know?
The only collectibles that appear at night are the memory shards, and are easy to spot. Try to get as many as you can during each night phase so you don't have to backtrack too much; be systematic. Yep, many chests can only be accessed later with newer magic(s). At times you must use the environment (exploding barrels, water, etc.)