I don't think there is any airbus reference for this. All the airlines I have been with cover this with SOP's. My current airline prohibits the use of Open Descent mode below 1500' AAL and limits rate of descent to no more than 5000 fpm above 5000'. No more than 3000 fpm above 3,000, not more than 2,000 fpm above 1000'. My previous airline just had an SOP that you should be not less than one minute from hitting the ground i.e. if you are 5,000' above the ground then v/s is limited to 5000fpm, 4,000' AAL then 4,000 fpm etc.