google-tag-manager add identify properties to dataLayer

Hi,

Currently the Segment identify method does not push any user properties to the GTM data layer. Should it?

in the app code

 window?.analytics?.identify('userId123', {
      account: '12345678',
      contact: 'john.smith@company.com',
    });

but when you console.log the window.dataLayer, you only have the page event which is missing the user properties like account and contact

[{
event: "Loaded a Page"
gtm.uniqueEventId: 1
path: "/blah"
referrer: "blah"
search: ""
segmentAnonymousId: "123123123"
title: "blah"
url: "blah"
userId: "userId123"
}]

This means if I want to use the account property as a dataLayer variable in GTM then I need to explicitly call an eventless track on page load with it, or inject it into the dataLayer manually.

Both approaches seem to go against the Segment best practice.

What should the expected behaviour be?

Reproduce the Segment identify call shown in the issue and inspect window.dataLayer in the Google Tag Manager integration. First determine the intended identify-to-dataLayer behavior and review existing integration entry points and tests, which the issue does not name. Done should define and verify how account and contact become available without an eventless track or manual dataLayer injection.