This is absolutely hilarious. The infuriating window corner roundness in Tahoe has been bugging me too–and this is a brilliant take on the problem.
Instead of disabling SIP and patching system apps to remove the rounded corners (which is the usual approach), this simply forces a consistent corner radius across all third-party apps via a DYLD-injected dynamic library.
It’s a small thing, but inconsistency in UI chrome is the kind of detail that, once you notice it, you can never un-notice. The fact that Safari has different corner radii from other apps is inexcusable–and that’s before the Liquid Glass disaster made everything look like a Fisher-Price toy dipped in vaseline. I appreciate the “if you can’t beat them, at least make them all equally ugly” philosophy here.
The implementation is old-timey, straightforward Objective-C method swizzling on NSThemeFrame–nothing exotic, but the approach of skipping com.apple.* bundles and only touching third-party apps means you don’t need to mess with SIP at all. That alone makes it worth bookmarking.