Currently there is no way to onboard a true ETSI SOL004 2.5.1 CSAR, because current validators do not check for the TOSCA.meta entries aligned with the ETSI SOL004 2.5.1 specification.
Implement a validator for the model "ETSI SOL001 2.5.1" which follows the ETSI SOL004 2.5.1 CSAR specification, allowing to onboard packages that are aligned with the specification when selecting the "ETSI SOL001 2.5.1" model.