I thought we were done with the myth that once we understand something, we don't need to memorize. I've come to the realization that memorization is a core competency. The more I have memorized, whether it's syntax or concepts or problems and how to solve them, the better equipped I am and the more productive I am in the future when faced with even novel problems. Memorization saves me insane amounts of time in day to day programming and gives me an edge in being able to solve and understand problems. I don't just have a deep understanding of the code bases I work with, I have a lot of details memorized about what parts there are, how they work, how they're interconnected, certain technical details, etc. And sure, I could just check, but when having meetings about technical problems and planning our projects, it's an insane help to know so much off the top of my head and that I only need to check a handful of things.

Spaced repetition is nothing other than intentionally refreshing something you currently know, to ensure that in a month or a year or longer, you'll still know it. It's not your place to judge what to memorize or not. I'd suggest you should also use spaced repetition on the methods and ideas, since we're very prone to forgetting that too. I would also never criticize anybody for memorizing something, since it's literally just doing intentionally what we would otherwise do haphazardly and by accident.