PenciDesign Supporter replied
Hi,
Google Tag Manger adds scripts through user-defined logic in tags. You should get access to your GTM account, find tags that load scripts and do exactly the same to them.
On the other hand, Unless your GTM container contains mountains of logic, defer should not differ from async in any measurable way, but it may harm the data that GTM collects.
Say, in case the page loads longer, and the user doesn't wanna wait and just quit, you will not know about that bounced user since GTM is deferred. I'm sure there are more edge cases in events timing in case you use datalayer or if GTM relies on other event listeners that could fire before the page is done loading.
Regards,
PenciDesign.



