That access point fernco kinda scares me. I could see myself pushing that thing right down the pipe. A saddle tee would make more sense. I'm not sure what the ipc think thinks about saddle tees for C/O.
Buy cheap, buy twice.
I am with Ben, hard to see clearly but it looks like that "plug" protrudes into the existing pipe. wouldnt that possible cause a stoppage? I am not sure about saddles as cleanouts for the IPC but it doesnt seem like that bad of an idea
But they are doing it in Europe like pex it must be good!