More valuable than securing the Rugby Championship title or winning the historic 100th test against the Springboks is the steep learning curve the All Blacks absorbed after surviving a relentless, smothering onslaught in Townsville.
Prior to their tense 19-17 victory on Saturday night, the All Blacks had not played the Springboks for two years, since their 2019 World Cup pool match. And it showed.
All the planning and analysis can only go so far in preparing a team to face the Boks.
Despite knowing exactly the style they would confront, the All Blacks struggled for large parts to counter South Africa's kick-heavy, defence orientated, slow, set piece focused tactics.
On the whole, Foster was pleased to escape with victory, thanks to Jordie Barrett's clutch 77th minute strike, but he admitted many of his team would take several lessons away from a match the Springboks succeeded in reducing to a dogfight.
The All Blacks planned to negate the Boks defensive line speed pressure by being direct with their carries and dominating the cleanout. As they discovered, though, it's one thing to make a plan, another to execute it.
"You can talk about pressure and about being strangled," Foster said. "We spoke a lot about the way the South Africans would play against us. It's one thing to dismiss it as boring, which a lot of people do, but I used the words ruthless and clinical and they're very good at it.
"We ran out of time in many situations and that put our skill set under pressure so it's a real learning curve for us in that space, particularly some of our backs. I felt our timing was a bit off because of the pressure we were put under.
"Isn't it good to learn that lesson and have a win next to your name? We're really excited by not folding. We didn't get too flustered, we kept playing. I'm overall happy and can't wait for next week now."
Foster acknowledged the All Blacks' handling – they conceded 23 turnovers – in the face of the Boks line speed pressure was not up to standard. Their lineout also lost four throws, some of those within striking distance of the Boks line. The rolling maul struggled to penetrate the green wall, and the All Blacks back three endured a difficult night under a barrage of Faf de Klerk box kicks.
"The performance wasn't really what we wanted but we were forced in a lot of areas by their pressure. That was a game we expected to come up against," Foster said.
"I loved our attitude even when things weren't going well. We wanted to play. We showed a determination to keep fighting and got there in the end.
"We made more errors than what we wanted to. Some of our handling wasn't at the level it needed to be. There's a combination of players playing South Africa for the first time; the pressure they put us under and you have to execute at the top level.
"It's a nice little message for us. Our wings had a real examination. Some things went their way but a few things didn't."
With their backs to the wall and time running out Foster praised his side's composure to steal victory at the death with rookie second five-eighth Quinn Tupaea coming off the bench to win a breakdown penalty, and Barrett stepping up to nail the 43-metre strike.
"It's really significant for us. We knew it was a big game. We've had a bit of an edge over them recently but you saw how fine the margins are. Hats off to Jordie – that was a tough kick. Our bench came on really well. Quinn did outstandingly well to win that turnover.
"Jordie will be the guy who won the 100th so good on him."
Given the long list of absences, including Sam Whitelock, Dane Coles, Aaron Smith, Sam Cane and Richie Mo'unga, Foster was satisfied to lock away the Rugby Championship, Freedom Cup and honour the passing of All Blacks great Waka Nathan.
"We are making strides on the physical side of the game. We are making strides in our ability to deal with set piece pressure. Clearly, we're not the finished product yet, we know that, but I loved the way we stayed in the fight, muscled up and problem solved.
"We've got a mission we want to achieve and tonight was a massive part of it. In the Six Nations if they win five games they celebrate it as a grand slam. We've got that chance now in the Rugby Championship next week."
Indeed, next week's rematch will reveal just how many lessons Foster's All Blacks absorbed.