Since GA4 dropped a feature called ‘annotations’ (https://www.lovesdata.com/blog/google-analytics-annotations), it would be a great addition to ahrefs. Especially when you want to mark a certain event, say for example redesign of a specific page or changes to your hreflang tags. User should be able to select a date and fill a description. Hovering over any timeline should display the annotation, which could clearify certain peaks in data for example.