Do I need another GTM template to send Google Consent Mode v2 signals, or does OptinStack handle the default and update calls?
OptinStack drives Google Consent Mode v2 automatically. On initialization it creates dataLayer and a minimal gtag function if needed, sends the first consent call as default with wait_for_update: 500, and sends later changes as update calls.
You still need GTM or the relevant Google tags on the page to consume those signals. Place OptinStack before those tags. Tracker blocking is a separate enforcement layer based on your published inventory and manually tagged resources.
Documentation: Google Consent Mode v2 and Google Tag Manager integration guide.