GA4 recently added two new event parameters: batch_ordering_id and batch_page_id.
batch_ordering_id
batch_ordering_id: I think it is a sequence or a count.
batch_page_id
batch_page_id is the current timestamp of the sent event (13-digit timestamp), which is basically the same as the current time from the cookie named _ga_<container-id>.
For example, if I trigger an event on bbccss.com, see the name _ga_<container-id>,referral to:In-depth Understanding Session in Google Analytics 4:
The current timestamp in _ga_<container-id> is 1700107169 (10-digit timestamp), and the batch_page_id is 1700107168937 (13-digit timestamp).
current timestamp=batch_page_id/1000