Hello @Dm_0001, I can help you with that!
You can find the answers in this documentation page: Working with Modular Characters in Unreal Engine | Unreal Engine 5.5 Documentation | Epic Developer Community
But to answer your question, you’re right about the Construction Script! All you need is to add a Set Leader Pose Component node and connect your main character to the Leader Component and all the clothes to the Target. This will also work for cinematics.
You just need to make sure your clothes meshes are children of the main character mesh and that their skeletons are compatible.
I hope this helps, please let me know if you need any more assistance!