Hey, despite not having any particular GA oriented guide to provide I do have some personal experience to share in how to go about using analytics tools to UX advantage.

From my perspective the first thing I wanted to gather was what to measure and how to measure it, basically defining the UX KPI's I wanted to observe. This goes beyond the "regular" ones like Conversion, Acquisition, etc. I wanted to answer more specific UX questions, such as: which terms are been searched? Which tabs are been explored? Do people add items from the list or the detail page?

As a mobile developer we've used references such as Baymard's Mobile E-Commerce Usability, Google's Mobile App Ux Principle, among others to do the following:

We've created a spreadsheet on Google Docs with 3 sheets: 1) The first one was for all the direct metrics I wanted to gather (bottom bar taps, add to cart from different places, etc) 2) The second one was the funnels I wanted to create from those metrics, for instance: add to cart > open cart > begin checkout > checkout steps > purchase. 3) The last one was for KPI's that required custom calculation to achieve, such as Product traffic vs Conversion rate.

THEN we've teamed up with developers to check how easy it was to register all those events and which metrics were actually event parameters, in order to tackle this part we delved into the GA documentation in order to find the right tool for each of this metrics,

During this process not only we discovered a ton of nice features of GA, but we've found out that some visualizations we needed we're built into it (looking from this perspective we should've done this sooner), to mention a few: 1) The User Flow feature is very nice to see user navigational behavior and bounce rates 2) Creating filtered views of users that belonged to a certain group to evaluate differences in the product use.

The good thing is that now we've familiarized enough with the act of how to measure stuff that it's easy to change platforms without much impact. In some other products we've used Firebase with Fabric to substitute GA, and it was much easier to do so.