Like I said - it would be a huge pain to replace, just not as bad as if it were the blob.The chip with a 1 on it is the TCT-6801 GOAC. It would still be a major pain in the ass to get another GOAC in there, especially with the presence of that mysterious glop-top labeled 6. Even if that glop-top wasn't there, you would need to manufacture a completely new PCB for the GOAC you want to use in the adapter.
Neat video!Also, before I forget, I uploaded the first part of RetroGen Adapter vs. Original Hardware on my YouTube channel. You can see the adapter in action against a 1991 VA3 Genesis Model 1 and a 1992 VA5 Japanese MegaDrive Model 1: