Since macOS completely changed the menubar architecture in macOS 27 the tools I was using were no longer working at the time, so I decided to build my own. Hadn't build an app in over a decade and things have changed so much since. I'm a design director so of course special attention went in the user experience and aesthetics (Settings with previews, subtle reveal animations, drag&drop and much more)
So macOS now knows how to hide icons natively, it does it when a Mac is locked down for an exam for example, Pelmet reuses the hiding part which then lets macOS know which icons should stay visible. The app does call on a private framework (MenuBarClientCore) resolved at runtime and has a safety net in case it fails, it reports hiding is unavailable instead of breaking the bar. Everything else (positions, clicks, previews, etc.) uses public APIs (Accessibility, ScreenCaptureKit).
I'm amazed with the reception Pelmet got, seems I wasn't alone to want a simple menu bar tool that does one thing, and (hopefully) does it well ;) Pelmet was built in native Swift, requires no accounts, no analytics, it's just private. Only external call it does is Sparkle for its updates. The project is free and open source (GPLv3) and hopefully makes many people happy.
Get the calm back in your menu bar and happy to answer questions