Please note that the SEO Web Vitals feature is exclusive to Matomo On-Premise and is not available in Matomo Cloud.
You should generally make a habit of checking on these scores regularly as websites tend to pick up bloat and slow down your own time. One last trick that can save you hours every year instead of manually checking these reports is configuring Custom Alerts for your SEO Web Vitals. These alerts can be dependent on a specific metric level, for example, your mobile Page Speed score going below 50 which would bring it into the range of Poor scoring that can cause issues for your SEO. This would look a little something like the following:
Alternatively, if you don’t want to wait for it to hit a certain problem level before being notified, you could set up an alert that notifies you when your score has decreased by a certain percentage. This can help you to quickly identify problematic changes to your web pages and would look a little something like this:
For more details on configuring alerts in general, you can refer to the Custom Alerts documentation which details how you can set up any number of alerts that get sent to you via email or SMS when certain conditions are met.