performance - Meteor autoform unresponsive script warning -

I am using aldeed: autoform in my meteor project for a bigger form:

The form contains several common fields and an array field. There are about 5 fields for each array item. When there are only a few entries in the array, then everything is working fine. But if the number of array objects increases, the page slows down (if there are more than 10 array objects, 1-2sec is taken before clicking on the "plus" symbol to add the item) It also takes a long time. With 15 array objects, it takes more than 30 (and takes all CPUs during that time). The main problem is that the script becomes unresponsive during those 30s and the browser raises a warning that the user has a script (which Tells to stop the meteor) But an array with 15 items is for a very normal use. What are the ways to increase performance of the autoform? (Maybe some features are not responsive?) How can the browser's warning be saved?

I am using default aforeffield.