I think we might be using the term "stress" in different ways.

This paper makes a distinction between direct operational strain and harm created by governments' responses (like adding fees, procedural barriers, and other types of friction in the system). The second part is where my concern is, when bureaucracy is meant to suppress questionable claims it can also delay or deter legitimate benefits.

The paper says it doesn't/can't make definitive claims about AI's impact, but says the strain is moderate. The conclusion does not seem to suggest any severe operational risk to these agencies/systems. Only 9 of 84 potential cases involved benefits or social protection, and it says most cases are good-faith users.

So, I do question what in the paper would show that the burden is large enough to jeopardize benefits? The main finding seems to be that friction in the system may itself effectively deny legitimate access.

Response to your edit: the $186 billion is GAO's government-wide estimate across 64 different programs and not a fraud figure or addressing individual benefits. It contains administrative and document errors, indeterminate payments, and underpayments. And expecting integrity in a system doesn't prevent criticism in the form of asking whether added enforcement bureaucracies cause more harm to legitimate beneficiaries than it prevents in that system.