Duplicate submissions when user double-clicks submit

Hi,

We’re seeing duplicate submissions on Contact Form 7 when a user double-clicks the submit button.

On double-click, we see two AJAX requests are sent almost simultaneously
CF7 processes both, so two emails are sent (confirmed via WP Mail Log).
This results in duplicate entries in our Google Sheets integration too.

We’ve tried: disabling the submit button on click / submit events (JS), locking the form using submit and pointer events, and server-side validation via wpcf7_validate to block duplicates

However, very fast double-clicks can still result in two valid submissions being processed.

Is there a recommended hook or method within CF7 to prevent processing a second submission while the first is still being handled?
Or reliably detect and reject duplicate submissions at the CF7 level?