The Expert Group on SMRs (EGSMR) of the Committee on the Safety of Nuclear Installations (CSNI) addresses safety challenges and develops a scientific basis which supports safety demonstration of the advanced and innovative methodologies and technologies used for SMRs. In a comprehensive report published in 2023, the EGSMR identified SMR safety related gaps of knowledge, cross cutting safety issues and provided recommendations for co-operative activities. Since then, the CSNI, through its working groups and joint undertakings, has launched several activities to make progress on the safety assessment of SMRs. More generally, cross cutting safety topics have recently been investigated deeper through national and multilateral initiatives. These include the reliability of passive systems, transportability, application of defense-in-depth principle for innovative designs, remote/autonomous operation, multi-unit/module probabilistic safety assessment, human and organizational factors, emergency planning zones, fuel safety and more.