Yes Antonia, I cover almost everything I sow and plant from now on, for three or four weeks, to help establishment. New plantings especially, little leaves blowing in the cold wind otherwise. This is a spring for fleece, ultra!
And you are right I do not cover autumn sown beans, for the reasons you give! They are tough as boots and do not mind cold, as long as their stems are not too long when it is really frosty. You could sow more broad beans now if you have room. If you still have 50% surviving, they will tiller and make new stems.