What inspired this wish list request? We're building a tool that loads well-documented data sources to JMP (a data mesh, essentially). We'd like to reveal the documentation about column governance, data types, and meaning to users conveniently. We can add these details to the Notes property, but this isn't highly visible.
What is the improvement you would like to see? When hovering over a column header, if the Notes property is defined, show a tooltip containing the column notes. Practically, this would display in just the same way Event Handler tooltips display, but rather than being defined at the cell level, it's defined at the column header.
Why is this idea important? Well-documented data sources allow other capable data-workers to understand, work with, and gain value from the data sources generated by others. For us, this means that the scientists who deeply understand, say, protein chemistry can create data tables with notes that allow those of us (like me) who don't really know what a "pI" is to use the dataset fluently.