I was wondering if Lightspeed is going to add in the near future as one of their e-commerce features Google Tag Manager. Currently, the process you propose has consequences. Ideally, as a user will be great to have a more straight forward process without the risk of loosing the updates to the templates. Additionally, will help with the organization and the administration of multiple pixels, code, etc that the industry is forcing us to all business owners to implement if we want to be competitive in the market. I am sure that this feature will benefit the LS community.
Other e-commerce platforms, have the integration already .
The above workflow of enabling the theme editor will be obsolete very soon. There won't be a specific Tag Manager field but we are adding the option to add custom code to the <head> of the shop.
This will allow you to copy/paste the code provided by a third party (GTM) and just past it in the back office.
Although we do not provide any timelines on exact implementation, this feature is very far in development and will be released soon. Keep an eye on the change log in your back office!
Have a great weekend :)