Is there a way to view all projects in a column view, with one project per column and all tasks per project in each column?
Nope, not yet
You could manually set that up, depending on how many projects are involved. You can create the board and name all of the columns for each project. Then you go into each project, select all tasks and multi-home them in the board project, making sure you add them to the right column. You’d then have a master board that would be in sync with each project.
The only snag is that you’d always have to remember to add new tasks to that master project, or they won’t show up.