SharePoint List calculated group ID

Hi there,

I've got the classic issue of a list growing over 5000 items and something in a PowerApp breaking.

In this case, the largest of a value would be found and +1 added to the next patch for a group of submissions.

I've figured, why not see if this can be calculated instead but unsure what values to use that are unique for rows that get added all at the same time.

Wondering if there is a script for something like - from oldest to newest created in the list - if you share the same created time you all get the same GroupID value (starting from 1), and the next set get that  +1 and so on?