What's the practical fix over and above this check I guess is my question?
Ground all the a/c! You will never completely eliminate the possibility of human error. Make sure your procedures are as water tight as they can be and train pilots accordingly. The final line of defence is TCAS.
As regards rate of climb/descent most operators require max rate 1,000 ft a minute when within 1,000 ft of a cleared level to avoid nuisance TCAS alerts.