To your population question.

Eco population is - simplyfied said - a projection of objects from the z axis "down" to your object you want to populate. Like creating all items up in the sky and then drop them onto your object. So the answer is "no" i fear, you can not populate just one surface of an object.

We should not forget, this technology is very young here, just one year old and i would say - version 1 so to say.

One day your ship comes in - but you're at the airport.