How can I re-use Simulink code using PLC Coder?

I've got a Simulink model which uses model referencing quite a bit. One example is a button debounce model which is being referenced quite often in my top-level model. Model references are awesome: I can change the code, and all references will change along with it.

Now I'm converting my model to be used with Simulink PLC Coder, but that doesn't support model referencing.

source: https://au.mathworks.com/help/plccoder/ug/structured-text-code-generation-limitations.html

Reading the MathWorks pages with PLC Coder supported blocks, I found the following statement: "A code reuse subsystem is a Subsystem block with the parameter Treat as atomic unit selected and the parameter Function packaging set to Reusable function"

source: https://au.mathworks.com/help/simulink/slref/subsystem.html

Question:

Say I've got 10 button debounce model references in my current model. I just replaced all model references with regular subsystems, according to the beforementioned instructions. Now I decide to refactor the button debounce code. Does that mean I have to manually go through all 10 button debounce subsystems to update them?

This seems to go agains general coding best practices and seems to be rather error-prone. I have the feeling I'm missing something here. Does anyone know a better way to do this?