I'd expect the widget to be read-only when enabled is set to false. Indeed, the popup won't open, however, the value can still be altered by clicking the X icon in either the chips (to remove individual values) or the entire input (to clear it). I suppose this is not intended behavior?

If it is intended behavior, I'd like to see a readOnly property, which would:
a) disable the popup (like enabled = false does)
b) hide the X icon (or custom delete icon) in the chips, or at least disable its tap handler
c) hide the X icon for the entire input

Is this something you'd be willing to implement or accept a PR for?