Waste lines laying on ground?

Is there any concern with laying ABS drainline directly on the ground throughout the crawlspace. Other than possible grade issues.

Not sure what you are asking; As for the ABS making contact with the soil no it is buried on a regular basis. just lying on the ground with no supports the proballity of draining properly would be nil.

I am visualizing from your pic’s;-) a very poorly crafted installation

I don’t think it would be a problem if it had the minimum required slope of 1/4" per foot to allow for proper drainage.

The only problem i can see is that it would be hard to crawl over for future repairs etc…also a good place for spiders and snakes to hide…just not a very clean look either and not very professional which would lead me to look for other problems. It would be functional though…