The question I have now after reading this paper (which was really insightful) is do the models really get worse under load, or do they just have a higher varia

The question I have now after reading this paper (which was really insightful) is do the models really get worse under load, or do they just have a higher variance? It seems like the latter is what we should expect, not it getting worse, but absent load data we can't really know.