Sorry to bring this up again, I was just looking at your source code to see if I could mod it to work to let me do this, it might but I'm not sure (My plan is to initialise a list of dutchies that are preserved with kingdom shattering, but my experience with C++ is very limited, I code mostly in Java/MATLAB/Python). But I was just remembering that you can shatter kingdoms like empires. Would the code let me say assign a kingdom to someone within the HRE, shatter the HRE down to kingdoms, and then shatter that kingdom down to dutchies but keep those dutchies in the HRE? (Is that just something I would have to try to see if the multi-level shattering would work) Obviously, the shatter_empires.txt file says not to shatter the HRE but it doesn't say anything about its vassals...
Thanks.