Hey,
Thanks for reaching out to us!
This is a great question. I plugin should work with most WordPress themes. However, when we do see issues or conflicts with themes it’s usually due to the theme having a heavily customized way of customizing the front-end of the site. For example, any theme that markets itself as a “drag and drop” type theme has a higher likelihood for potential conflict.
That being said, we do regularly test our themes against the default WordPress themes (Twenty Twelve, Twenty Thirteen, etc.) and those could be a great place to start.
Let me know if this helps.
Thanks!