I found that the "udm" trick disables all "rich content" in search results (ie: stuff that isn't a plain text search result link). But adding the following user rules in AdGuard for Safari does the job:

  google.com###m-x-content
  google.com###B2Jtyd

Previous discussion: https://news.ycombinator.com/item?id=40450267

Safari extension: https://news.ycombinator.com/item?id=41298312