Multiple selection for project assignment

If I have a user open in the Employee view and want to assign them to several projects (e.g. new employee), I have to click in the field several times and can only select one project at a time. This is very time-consuming for people that I want to add to a large number of projects. (It would be the same if I went the other way via the project view).

It would simplify things a lot if the list of projects (with as many visible projects as possible) was expanded and there was a checkbox in front of the projects so that I could click on several projects and then save them.