The devil is in the details.
A typical situation which happens on a daily basis: ICE/BP stops a bus of 40 passengers for which there is "reasonable suspicion" of illegal aliens on board. Do you think it's a good idea to force the BP/ICE agent to fill out 40 detailed reports for 10 minutes of questioning? It looks like a tremendous waste of manpower.
I agree with
@Fawlty's perspective that it would be good to have more data on stops, but it appears that Gillibrand wants a detailed report for every single person on board. The cynical side of me thinks that this would be a means of preventing ICE/BP from doing their jobs, that Gillibrand knows this, and that she is pushing this as a means of getting ahead of the Democratic primary competition. It's red meat for the left-wing base.