TL;DR
Trying to find a needle (one train waiting at the head of the queue) in a haystack (50+ trains all waiting to get to the front of the queue)What ?
My suggestion is to sort the search results in the Trains GUI by any differences in the trains matching the criteria, particularly such as state (Waiting at versus Heading to).The new Trains GUI is amazing, and the search function is great.
In my use case, I have a storage area organized as a queue for available trains. There are always a few, but sometimes such as when I am doing massive deconstruction to redo a large area of my base, there are dozens or hundreds. When I need a train, I grab the next one from the front of the queue.
Currently all trains meeting the search criteria are included in the search results in random order. When there are only a few, it is easy to grab the one from the front of the line. When there are dozens, I either hunt through pages of trains trying to find the one that is Waiting rather than the dozens that are Heading to the queue station, or I click on the first one, go to map view, and then select the train at the head of the queue.