I have a similar problem (nothing to do with the users service though) with a set of data that I am not actually using yet in production so I’m not going to panic.
After thinking about the problem for a minute or so I think the pattern that emerges will probably result in something similar to the old behavior through the use of controlling your own set of multiple trips.
Edit: Don’t do any of that, read below this post and use: q.fetch_only()
̶.̶.̶s̶o̶ ̶o̶n̶e̶ ̶s̶e̶a̶r̶c̶h̶ ̶w̶i̶t̶h̶ ̶̶̶̶q̶.̶o̶n̶l̶y̶_̶c̶o̶l̶s̶(̶)̶̶̶̶,̶ ̶a̶n̶d̶ ̶t̶h̶e̶n̶ ̶a̶ ̶s̶e̶c̶o̶n̶d̶ ̶r̶e̶t̶r̶i̶e̶v̶a̶l̶ ̶s̶e̶a̶r̶c̶h̶ ̶f̶o̶r̶ ̶e̶a̶c̶h̶ ̶r̶o̶w̶ ̶t̶h̶a̶t̶ ̶y̶o̶u̶ ̶n̶e̶e̶d̶ ̶t̶h̶e̶ ̶s̶p̶e̶c̶i̶f̶i̶c̶ ̶d̶a̶t̶a̶ ̶f̶r̶o̶m̶ ̶w̶i̶t̶h̶ ̶a̶ ̶d̶i̶f̶f̶e̶r̶e̶n̶t̶ ̶̶̶̶q̶.̶o̶n̶l̶y̶_̶c̶o̶l̶s̶(̶)̶̶̶̶ ̶t̶a̶r̶g̶e̶t̶e̶d̶ ̶a̶t̶ ̶t̶h̶e̶ ̶f̶o̶u̶n̶d̶ ̶r̶o̶w̶ ̶o̶b̶j̶e̶c̶t̶.̶
̶Y̶o̶u̶ ̶w̶o̶u̶l̶d̶ ̶d̶e̶f̶i̶n̶i̶t̶e̶l̶y̶ ̶h̶a̶v̶e̶ ̶t̶o̶ ̶w̶a̶t̶c̶h̶ ̶c̶l̶o̶s̶e̶l̶y̶ ̶h̶o̶w̶ ̶u̶s̶i̶n̶g̶ ̶t̶h̶e̶ ̶d̶a̶t̶a̶ ̶f̶r̶o̶m̶ ̶a̶ ̶r̶o̶w̶ ̶o̶b̶j̶e̶c̶t̶ ̶t̶o̶ ̶r̶e̶-̶r̶e̶t̶r̶i̶e̶v̶e̶ ̶m̶o̶r̶e̶ ̶c̶o̶l̶u̶m̶n̶s̶ ̶f̶r̶o̶m̶ ̶t̶h̶e̶ ̶s̶a̶m̶e̶ ̶r̶o̶w̶ ̶w̶i̶l̶l̶ ̶i̶n̶t̶e̶r̶a̶c̶t̶ ̶w̶i̶t̶h̶ ̶t̶r̶a̶n̶s̶a̶c̶t̶i̶o̶n̶s̶.̶