I saw in release notes for 3.5.0-exp there is a mention of removing Physics from builds and it points to this webpage in the docs but I can’t see where it mentions marking Physics to be stripped? Deployment & Compression | Needle Engine Documentation
Not by default. But you can set it to Auto and it will search for colliders and rigidbodies in the current scene and then exclude/include it accordingly. It doesnt search referenced scenes or prefabs right now tho