Please give us an option to set the number of columns in a board manually. A fixed number of colums that does not change when resizing is essential for the ability to “creatively” use the space on a board. I often use a fixed four-column view where the rightmost column is for less-important stuff, the third column is empty for spacing, and the two left columns have important sections. This cannot be feasably realized when the number of columns changes dynamically. It is less important if the design breaks on smaller window sizes. Mobile view should still be one-column though, I believe.
Or give us an option to switch between “dynamic number of columns” and “fixed number of columns” for each board individually.