Currently, Google Optimize does NOT currently allow you to:
do heatmap analysis to better understand to user behaviour on your site
use your existing goals and metrics in Google Analytics as experiment objectives
test new website designs, layouts and content with a subset of your visitors
serve experiments to specific groups of users that you’ve defined as Audiences in Google Analytics
Explanation:
You can test new website designs, layouts and content with a subset of your visitors. Optimize leverages the power of Analytics by measuring all experiments natively with Analytics, allowing you to use your existing goals and metrics as experiment objectives. What’s more, you can serve experiments to specific groups of users that you’ve defined as Audiences in Analytics.
Read more here: https://support.google.com/partners/answer/7336695