Thanks for the response,  using option 1 and 5 are not an option for us as we're trying to do this through our Shopify app FigPii,  Regarding using ScriptTag API based on the documentation provided here ScriptTag the only value allowed for 'event' is...

Our tracking code should be loaded with page initiation or at the latest DOMContentLoaded. Our users use our app to run AB tests on their store and make modifications to their pages.  When our app load is delayed, there's a noticeable and unpleasant ...