const options = { } // All user data options to be sent to Segment

// On each full page refresh: Start with the identify normally, excluding Chameleon
window.analytics.identify(123, options, { Chameleon: false });

// Then: Send the uid_hash to just Chameleon
window.analytics.identify(123, { uid_hash: 'abc-def', ...options }, { All: false, Chameleon: true });