Currently the only filters on input for Planning Optimization are related to which items should be included in the planning run or whether the forecast should be included (plan filters, runtime filters, coverage groups, etc.) but some businesses have scenarios in addition where they want to exclude certain data from being included. For example, a particular sales order or set of orders, certain forecast lines, or other criteria that may be specific to a business or industry.

In classic master planning, this is something that can be customized, but Planning Optimization only supports extensions for post-processing (Planning Optimization extensibility - Supply Chain Management | Dynamics 365 | Microsoft Learn). It would help more users adopt Planning Optimization if there was either a framework for doing more unique input filters or the ability to migrate their extensions to be compatible with Planning Optimization.