Legends are always a large part of my experience builder projects, used on nearly every page I have developed. Something I have noticed when using them is that they are not very editable, making them very limiting visually. The top bar of the legend is always this bring blue color that you are unable to change which tends to clash with the design of the project. Other elements such as spacing would also be very helpful to alter to the users preference. Overall, more editability for legends is something that I think would be very helpful and valuable for web experience builder sites.
