You mean like in non-sanctuary cities and states, where the local authorities just hand the criminals over in the hallway and there's zero need to roll into neighborhoods at all?

Ah, let's use that counterargument as an illustration of how a conservative can use this approach to try to argue within the frame of their interlocutor, who has indicated that he has a priority system that emphasizes the impact on the "good" unauthorized.

One can argue that "sanctuary policies" are also self-defeating, because local government cooperation with detainers can help ICE more effectively target just the "bad" unauthorized while not going after the "good" unauthorized.

But the flip side to that is that it also depends on how ICE uses their detainer requests. Are they using it to go after the "bad guys" in the hallway? The short answer is, "not especially":

In general, individuals with a criminal conviction made up a surprisingly small number of those targeted by a detainer. Out of 17,972 detainers issued between January 20 and February 17, just 28 percent had any prior conviction. Of these, despite this administration’s rhetoric, only 30 detainers were targeted at convicted rapists and just 65 at murderers.

In general, where a conviction was recorded, it tended to be for a less serious offense. The most frequent conviction was for drunk driving, followed by “other traffic offenses.” The category of “miscellaneous assaults” which excluded serious assaults was in third place. Convictions for illegal entry followed by convictions for illegal reentry were in fourth and fifth place. Together these five offenses were classified by ICE as the most serious criminal conviction recorded and made up one third or 34 percent of recorded convictions.

tracreports.org: Trump’s Ineffective Use of ICE Detainers: Numbers Jump but Few Produce Results

Now we're back in discussing the Ratio. Even the detainer process ends up bringing in a very high number of people that are either not criminals (72% have no criminal convictions, and the majority of people arrested don't get charged or convicted), or are people whose convictions are for traffic offenses or border entry crimes.

That puts us back on ICE's behavior. If ICE were more discriminate in how they used detainers, then they might possibly get better responses from local authorities who have different views on the right Ratio level. If ICE was mostly sending detainer requests for people like murderers and rapists, and not people with no criminal convictions, then local governments might respond differently than they do.