I noticed when you closed the pochade your finger once taken off,showed the lid buckled and a gap could be seen! Probably because it is a weak baltic pine top?. I like your design but I'm a little concerned about the lid not lasting. Let me know if you change that issue. regards
Lovely pochads box and a design thats copied by others too. I think though, that lower magnetic panel holder would drive me mad. I like a panel that's held level - especially when the opposit one at the top is. It just seems a bit messy. I'd be tempted to drill a series of parallel holes that would accept two pegs shaped like chess pawns. They could be stored in the drawer.
The level of the bottom magnetic panel support is not a problem at all. The top support is the level which you bring and line up your panel to. The bottom magnet support simply lines up naturally with the level established by the top support. Fantastic design