According to Google app script time-trigger documentation https://developers.google.com/apps-script/guides/triggers/installable#limitations, Time-driven triggers cannot run more frequently than once per hour. How can I use app script to write an add-on that process large amount of data?
If I run a trigger, it will only allow me to trigger once. I can't chain the triggers so it can continuously run.
You cannot do so using triggers because they would run at most once per hour in the context of an add on.
What you can do is to initiate such processing client-side while possibly showing progress on a sidebar. The client js in the sidebar can chain server calls.
Of course being all client-side means the user must have opened the file and if they close the browser tab or navigate away, the chain calls will stop. That can be handled by alerting the user and making them aware that a "sync" happens and sometimes takes a while. Currently there is no other way to handle this unless your client call and time trigger call another server which does the processing, like appengine or gce.
