It may be do-able. I don't think there would need to be a fake entity created for each construct because we can do the tests in any part of the aiscript.
The idea is to create a TOI (not a func_explosive) and trigger it from the map script each time a part of a base is built:
action 1 //our fake TOI
{
if_construct_built_true 2 //part of a base
kill_action 3 //the deliver action
if_construct_built_true 4 //another part of a base
kill_action 5 //the deliver action
}
If the constructs are set up like normal constructs, it should work. I haven't tested it yet, but will this weekend. The tricky part will be getting the fake toi triggered in a manner that will call the action test.
It may be something that we can use on maps like venice as well...