as far as I can see, there is no way to have responsive collection pages, right?
Maybe this would be a nice update to come soon
Responsive Collection Pages - what do you mean ?
You can add items to collections, but when you look at collections on a mobile device, the page does not fit the screen width, so you will see horizontal scrollbars. This is not very user friendly and also a disadvantage for Google ranking.
Item pages became responsive a long time ago, so I wonder if collections will be responsive in the future as well?