Hello
First of all, thank you so much for using the plugin.
Regarding your query, there is no such feature to merge the FAQs for now and you have to either use the individual FAQ for specific trips or the global FAQ which can be used as common FAQs among the trips.
However, we will list the feature as a requested feature and work on it in our future updates.
Also, if you want the feature immediately in your side, you can refer to Hire our Customizer service.
Hope this clears your confusion.
Best Regards!