Of course, Brais Calvo Vázquez discovered a new Alpha from GA4!
Cross-channel budgeting in Google Analytics 4 enables you to analyze performance trends in your historical data to help determine where to invest incremental dollars or adjust budgets for in-flight and future media initiatives.
Cross-channel budgeting includes the Budgeting Overview and the Projections Report.
Cross-channel budgeting is currently in a closed alpha and only available to those users!