Welcome to the forum!
I do not have the answer for the AiO, unfortunately. I can also confirm I have never seen an AiO cabinet with a G.fast pod. But I also have never actually seen an AiO cabinet in the flesh, so I actually have no idea what the situation is with bolting on pods - whether that is a copper extension or G.fast pod.
As for the "single door" PCP, no pod can be attached to these. If they wanted to install a G.fast pod, they would need to reshell the single door for a modern steel cabinet. The process is generally not complex and should not disturb any existing connections.