Hi @tfarrell
Oxygen offers full control over layouts across different screen sizes. So, for making posts responsive with the Oxygen theme, you typically won’t need a dedicated plugin , you should manage responsiveness directly within the Oxygen builder, using its built-in tools. You may check their documentation, https://oxygenbuilder.com/documentation/visual-editing/responsive-controls/
Also, this is a commercial plugin, we ask that you please go to their official support channel, so you can get support from the people who know it best.
Thanks