The content of a Multi-engine Skill Test and Proficiency Check is given in Appendix 3 to JAR-FCL 1.240.
Engine shut down and restart is part of the practical training for a MEP Class rating. There is no requirement to complete it on either a Skill Test or a Proficiency Check.
The latest version of the now combined LPC/LST Form SRG1157 Jan 03 shows it as an Optional item not a Mandatory one.