After realising too late it was pursuing a concept that would lead to a less efficient car design, the MCL60's draggy launch spec hamstrung the Woking team both in lap time and in its ability to overtake other cars.
In the meantime, it prepared a tweaked floor approach that saw the light of day at last weekend's Azerbaijan Grand Prix.
Behind the scenes new team boss Andrea Stella received a mandate to review the technical structure, with technical director James Key leaving the Woking squad and his remit split into three separate posts amid a hiring spree.
While the reorganisation came too late to influence McLaren's Baku updates, the belief is that it will speed up the next round of upgrades, which will amount to a "kind of B-spec" before the summer, as Stella called it.
In Baku McLaren already showed some minor improvement, with Norris collecting two points in ninth and rookie team-mate Oscar Piastri finishing just outside the points in 11th.
While still far removed from its goals, the update and the restructure have given Norris, who is contracted to McLaren until the end of 2025, more confidence that the team is on the right path.
"Definitely the guys and everyone back in the factory seem happier, like more optimistic," Norris said. "I have even more faith in terms of the new structure and some of the new people we have and things like that.
"Everyone's a bit more free and willing to try new things and make bigger steps."
On Sunday Norris was stuck in the DRS train behind Haas' Nico Hulkenberg for many laps, which illustrated McLaren's persistent lack of top speed, with the caveat that most teams found overtaking difficult in Baku.
"It's pretty much impossible to overtake, especially with our straight-line speed and with how short the DRS zone is now comparing to where it was last year," Norris explained.
"I did the best I could to try and keep up with the cars ahead. I just used the tyres up too much, because we're not on the same level.
And while there is more potential to exploit from McLaren's Baku upgrade on more representative circuits, it's the summer 'B-spec' that Norris is truly excited about.
"It wasn't going help that much in the very slow speed corners, so if you look at it on a pure lap time basis, it probably didn't help us too much here. A tiny bit, but not too much," he added.
"Maybe in Miami we will see some bigger gains with some of the more medium-speed corners. But that's it for now. It's a small step forward, more of a different philosophy to have a baseline with.
"We have things coming which are looking good and definitely bigger steps than we had this weekend."
Additional reporting by Oleg Karpov
