Trello – Archived Trello list. Cards disappeared. List doesn’t appear back on board

I agree with your friend about not dividing up into separate boards by type of job.

With your examples such as 'Design ideas' etc, I think they really do fit naturally within different lists on the same Board. It's exactly the sort of usage that Joel demoed in multiple videos about Trello.

The only thing I can think of, to help manage very long lists, is to use Trello's Labels system to put categories on cards, and then use filtering. You should definitely give meaningful names to the default labels.

I wrote up some tips on how to use labels recently.

Having said that, fairly early on the Trello on Trello board got huge, and eventually they reduced the scope of it. So it's does seem to be a well-known problem.

You have two ways you can do this, depending on whether or not you want to make the board public. Both make use of the comments setting found under the board profile.

If you make the board public, you can select "public" under comments in order to allow anyone with a Trello account to leave a comment.

If you don't want to make the board public, you can create a new organization for members of your team and members of your client's team and associate the board with that new organization. Then you can select "organization" under comments in order to allow anyone in the organization to leave a comment.

As a bonus, you can do the exact same thing with voting.