No banners. Notifications collect in the background, and you see them — grouped by app — only when you open the menu bar.
Free and open source. For Apple Silicon Macs.
The first launch needs one approval in System SettingsHow

Turn banners off in System Settings and notifications still arrive in Notification Center. Nonja reads them from there and builds a list. Nothing appears over your work.
Not one timeline but a bundle per sender, and each bundle's heading clears that app's notifications in a single click.
Clicking a row does what pressing the real notification does, opening the exact screen it points at.
A filled mark means something is waiting, an outline means nothing is. No count, so there is no number climbing at the edge of your vision.