This plugin is really good and I appreciate how clean and simple it is to implement. Not to mention the fact it’s free and lightweight too but having columns side by side on a lower res device is plain bonkers to me and I have no idea why the dev doesn’t “fix” this.
But as dotnordic said the fix is relatively trivial to implement yourself but I did make one !important change:
@media (max-width: 700px) {
.column { width: 100%!important;}
}