There is currently no setting for that, but ImageKit send a custom HTTP header with every scanning request. So alternatively, you could prevent your templates from being evaluated by adding the following at the very start of your template file.
<?php if(isset($_SERVER['HTTP_X_IMAGEKIT_INDEXING'])) return; ?>
Maybe you can tell me, what exactly breaks ImageKit’s crawler? I always try to build the plugin in a way, that requires the least amount of manual adaptions of existing code wherever possible. E.g. the crawler is able to detect 404 pages or redirect templates by their HTTP status code and treats them accordingly without resulting in errors.