Depending on the size of the serrations, you may be able to get the corner of the WEPS stones and plates in the grooves/arcs.
I know the added height of the Choseras and Shaptons will get in there, but it really does beat up the stones, and I personally question if it’s really worth it.
The best thing to do (IMO) is to sharpen the knife as if it were not serrated – it will still get the tips of the serrations sharp. Odds are the insides of the semi-circles are still somewhat toothy.
DO you have a picture of the actual knife?