Schedule with Dual Values for level heights
The ability to schedule a height. One related to the project height which could be something like 0; 3000; 6000... and one for the survey point which could be something like 44 000; 47 000; 50 000...
As for the level head family you should be able to pick which one your project and local building administration requires, or be able to create both and swap between as required.