Hi, is it possible to control the ERG Mode by using the Zwift Play Controllers? That was the most complicate thing with the Companion App with a heartrate of 180 in a sprint workout 
How are your general thoughts about Zwift Play?
Zwift Insider published a PDF showing how the controls work in different contexts. It looks like you can increase and decrease workout intensity using the side buttons if I’m reading that correctly. It does not look like you can switch off ERG mode from the controllers.
https://zwiftinsider.com/wp-content/uploads/2023/06/Zwift_Play-Control-Schemes-Preset-B-Revised.pdf
For general thoughts on the Play controllers you might look at these threads (there are others as well)
I would summarize it as some people are happy with them and have no issues, some people are able to use them with some workarounds, and some people find them completely unusable even after multiple support interactions, replacements, etc.