I was curious if anyone has used this feature during model running? If so, how did you go about the creation of the raster? I noticed WP used something similar on their NROC project.
Have you examined the users guide? The input required is cell-specific flooding heights in units of NAVD88. If you only have current storm surge height SLR will be added to it. If you have SLR-specific maps those can also be accommodated though the file naming convention is rather inflexible.
What is your specific question? Probably it would be best to start with the storm surge data that you have available and consider how to process that into the required raster format.