It may be a set of preferences for now, but it always grow into a monstrosity when future preferences don't align with current preferences. That's what accidental complexity means. Instead of working on the essential needs (having an admin interface that works well), you will get bogged down with the whims of the platform and technology (breaking changes, bugs,...). It may not be relevant to you if you're planning on abandoning it (switching jobs, side project you no longer care,...).

Something boring and standard is something that keeps going with minimal intervention while getting better each time.

Your team's fixed preferences get stored into your .agents.md file so you don't type it over and over.

If you change your preferences, the team refactors.

I'm going to go out on a limb here and say NextJs with Auth.js is pretty boring technology.

I'm struggling to see what you'd choose to do differently here?

Edit: actually I'll go further and say I'm guiding against accidental complexity. For example Auth.js is really boring technology, but I am annoyed they've deprecated in favour of better Auth - it's not better and it is definitely not boring technology!