/togglepreview is a great command. However, people often forget it exists, and it can be confusing for new players. Additionally, switching between servers resets your state, and it can be troubling if you're switching between shops and personal storage on the same server. Why not make it a little bit smarter? My proposal is to have preview toggled on by default on residences where one does not have container flag (or the flag for the specific container, e.g. container:chest), but does have container:preview flag. This way, players need not toggle it on or off when switching between their own residence and shop residences. Additionally, a nice thing to go along with this would be a small message when adding the +shop tag, along the lines of: "If you want players to have the ability to preview your stock, use the command /res set container:preview true".
