Difference between node-cron module and Heroku scheduler

I have a node application running on Heroku.
I want some jobs to run periodically every few seconds in order to fetch data from an external MySQL database to my MongoDB.
After searching extensively, I have found many ways to do this.

My problem: I cannot fully understand the difference between the cron module and Heroku scheduler and the pros and cons.

Some differences I noticed:
If I use Heroku Scheduler, there is a 10 minute limit.
If I use the node-cron module, I run it in the main index.js file and it will run every few seconds if I want to.

But how do these two methods affect when running multiple speakers?
In this case, the scripts will run multiple duplicate times?