So you always expand your roms or hack only games with clearly unused bytes like sequences of 00 or $FF? The code data logger is really useful to get the most of the rom, specially without expanding it. Sometimes you can check the unused code itself to see that there's no way it can be called and is just leftover code. Some other times there are branches that never go to it, and you can analyze that to know if there's a chance it will be used or not. But this is why I always take notes of which bytes I changed, so if a bug happens I can move my code to a new place.
About the topic, add 20EDBC60 to 0x6204 and the block will be destroyed, but there are a few more things going on. You will need to create an exclusive routine that is like the one at BCED that doesn't do the extra stuff and then call it instead.