Yup, expressions are totally supported when rendering from AE to AME. The issue here is the CSV, but there's an easy fix. When you queue a comp to render in AME, a separate version of your .aep is temporarily saved out for AME to render (this is how you can render in the background and continue to work in AE without issues). However, only assets that are used in your comp are saved and referenced in this temp .aep, but your CSV, which I'm guessing is being directly referenced from your project panel, is not saved.
So, the simple solution (and this is good practice anytime you're dealing with data-driven animation) is to drag the CSV to your comp, just like any other piece of footage, and to update your expressions to reference this layer instead of the file in your Project panel.
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