You may be able to create this automation natively via Notion Database Automations. After you setup a Relation between each individual’s KPI database and the central KPI database, the logic could be this:
When page created (on each individual’s KPI database)
Create page in central database
And vice-versa if applicable
Similarly
When page updated (on each individual’s KPI database)
Update page in central database
And vice-versa if applicable