We define our releases as functional value based releases rather than time boxes. Nonetheless, it would be useful to use the Feature Board with time boxes (e.g. our Program Increments) across the top as well. The ability to drag and drop, rank features, etc. in the Feature Board is very useful.
Having the ability to switch orientations of the Feature Board would make it more intuitive for individual PMs to plan while also keeping the ability to tell the product story (if you will) "up and out" to executives, sales, etc.
To make it more generic, it would be useful if we can set the feature board to categorize by a different attributes. For example, we have a custom field with our Program Increment numbers. It would be great if I can set up a feature board to list the features by the PI Number custom field, rather than list by releases, so that I can move features between PIs without changing the release.