Susan,
I have used beeswax encaustic in the past on both photographic and conventional printmaking processes. I have never noticed any downside to using it, other than the yellowish color, but for me that is usually desired in the applications in which I have used it. I'm not sure exactly what acidic side effects you are referring to. For photographic prints, I have usually used toned silver prints, but have not noticed any ill effects due to the acidity. Alternatively, you might want to look into something like Japan Wax, made from the sumac berries, or Hydroxyoctacosanyl hydroxystearate which is a less acidic and commonly used beeswax substitute (for cosmetics), and is used in making emulsion stabilizers. I have not used either of those products however, so really have no idea of their potential application. I believe both are relatively cheap, so perhaps some experimentation is in order.
Can't wait to see the results!