As an author that is selling exclusively on Codecanyon. Am I allowed to offer a free (lite) version of my application (on my website). This can be good for promoting future sales
Not on your website Exclusivity Policy – Envato Author Help Center while you are an exclusive author
If your item is a wp item then according to Exclusivity Policy:
Are there any exceptions to exclusivity for items that belong to the same Product Family?
2. Envato authors of WordPress themes and plugins are permitted to offer lite versions (a version with reduced/limited functionality) of their exclusive themes and plugins for free on wordpress.org.