I'm not sure I understand the scenario. You want 1 block to push into 72 different schematics? How do you push into the correct block?
Placing 72 blocks would be simple with the array function. You could even put them down another level in hierarchy. DxDesigner can easily handle assigning reference designators using it's hierarchical database design.
For component level, Array Compent prorty with a quantity number can be assigned to the compoent for representing numrious component instances or use Dxdesigner's Array copy to automatically put numerious component instances at once. However, this property isn't supported on Block level, so designer need to to put multiple block instances,neither array-copy be supported(maybe its a bug )