Yes, the best way to trigger a signal in another flowscript, would be by using the SendEvent node, along with a “Events/Custom Event” node on that other flowscript. You don’t need to use SendGlobalEvent. The normal SendEvent will do, as long as you provide the node with the flowscript reference, either directly, or linking it to some other node or variable.
Let me know if you need a full example, or further explanations on that (or any other) matter.
Thanks!