A steep gradient in itself does not "prohibit" departures from a particular runway. Just take a look at the RW19 SID's out of YBBN, particularly via CORAL.
What is required is an acknowledgement of the obstacles and a contingency plan to deal with them (aka special OEI procedure). Each operator deals with this in a different way, so don't expect ATC to know what you will do in the event of EFATO.
In any case, a departure in VMC by day is not an issue, as obstacles can be seen and avoided.