PAEWANG + Hori FC4 dual mod help

I am trying to mod my current Pewang with the HFC4, but not sure if it can be easily done? Below is my theory on how it can be done, pictures taken from some other threads.
Credit to Nerrage dual modding 101 thread. (Dual modding 101
Thanks in Advance

I don’t see anything wrong with the diagram

As for how easily its Done?
Can you solder fairly well and know how to spice wiring, if so this should not be difficult for you

Yes I have modded before but just never tried dual modding.
Any tips or things I should be aware of?

The dual modding guide you mentioned is really good, there should be no extra difficulties with the boards you’re using.