I just came back from a good training session. Set up multiple (hidden) wingers with falls in knee high cover at ~80+ yards (varied depths). Walked to the line, told him to sit and mark. Did NOT line him up. Started out with a couple of singles and worked up to varied multiples but did not move my feet from the original marks. Left it up to him to keep track of the falls. The only cues he had were quacks from the winger remotes (we can't use primers where we train) before each launch. He did fine with no errors. After each retrieve he looked to the area of the next fall on his own.
I now realize the problem was my fault. No more cute tricks such as blinds before completing all marked falls. I was teaching him to not rely on his memory.