"It is pretty exciting, but we've got a few years to go, and a whole year to figure out what we're going to do at the next world champs."
Part of the issue is the Olympic schedule in Tokyo. It's not as if the spreading of events allows plenty of recuperation time in between. Some disciplines have racing as little as 40 minutes apart.
Walker has more concerns.
"To do all four is probably a bit too much at an Olympic Games, so we need to be strategic in how we choose these events for different people and how those athletes decide to focus on different events," he said. "It's not just Lisa. There's another squad of athletes coming through.
"Caitlin is our second female world champion. There's Aimee and Kayla, all fantastic athletes. How we spread our talents across all events is going to be very difficult and a careful decision for us all."
Walker's own view is medalling in three events, let alone having a crack at four, would be an outstanding achievement.
He takes a holistic perspective: the bottom line is success for New Zealand, rather than its stellar paddler.
"Some of the events, by the nature of the programme, make it hard to do together. That's probably the biggest challenge," Walker said.
Carrington contested 10 races on the Racice course, which was a remarkable effort. Her previous most at a regatta was six.
She's now up to 11 world championship medals, seven gold. New Zealand had never before won four medals at a worlds, the previous best being three at 1987, 2013 and 2014.
The K1 200m is a special favourite for three-time Olympic medallist Carrington, the event in which she sprang to prominence at the 2011 worlds. She produced her second fastest time in the event on Sunday night.
"It was really special to be able to come back from Rio [2016 Olympics] and to be able to perform.
"A lot of trust and planning went into it. Gordy, when he asked me if I wanted to do four events, obviously believed I could do it. But it's about making sure you spread your energy right through the weekend.
"Training with the girls in the K2 and K4 did change my training schedule a bit but it was a fun thing to do and it's nice coming out of an Olympic year and being able to do something different."
Now it's time for a break, for the paddles to be put away for a while. Then it's about dissecting how best to maintain a remarkable success story, through to Tokyo.
