A quick way of keeping your rendered images up-to-date without re-rendering them manually after changing the model is to use the 3D Only panel of the View Settings.
Instead of rendering the specific camera views, then saving and placing the final .jpg/.png/etc. files onto the layouts as static content, place a 3D View that is set to be generated in the PhotoRendering Window (not the default 3D Window). You can even store the different PhotoRendering Scenes in these settings for each and every View in the Navigator.
This way whenever the View is opened, or the Layout where the View was placed is updated – either manually or automatically – the image will be re-rendered as well.
In case of large models and high quality rendering settings it is recommended to set the Layout to Manual update for the same reason: to avoid re-rendering everytime you open the layout, even if it is just to have a quick look.