The edit group modal is hard to close from the keyboard

When editing a group (to add and remove members) from the group administration section, a modal appears: the group editor.

Pressing escape doesn't close the group editor. One needs to reach the (cross) close button at the top right of the modal. This close button is hard to reach because the "Users to add" field traps the keyboard navigation: tab and shift+tab validate the currently selected user in the dropdown that appears when focusing the field. Pressing escape then pressing shift+tab (several times if there are several present in the field) to reach the close button and then pressing enter correctly closes the modal, but I think this is a bit harder and more contrived than what it could be.

More generally I wonder if there is something to address the two following issues:

• keyboard navigation when selectize fields are involved
• have any focused modal close when the escape key is pressed