In the new home experience, when using the My Work widget to display projects in various different formats there is no option to 'collapse all' on the project name/heading.
Projects are displayed based on name/date/status. Clicking on the project name/date/status will collapse all tasks and requests within the project and 'minimise' it. This is not an issue if the user is working on a small number of projects (around 5-10) but if the user has a large number of projects (30 or more) it can be cumbersome and tedious to collapse each project one at a time to get to the one you are interested in.
Users would benefit from this as it would save them time by eliminating the need to collapse each project until they find the one they are interested in.