This may be more of a complaint than a bug, but I have seen this with other extensions as well. It just happens to be more egregious in this case due to it's size.
After deletion(unistall) the files in /home/tc/.conf remain.
In the case of chromium, that's a BUNCH of stuff still being backed up, even though it was discarded. This adds considerable time during shutdown and to me seems to be counter to the core philosophy of a light and fast OS. (I removed chromium specifically because it's a pig (IMO), not knowing that it left this huge and unnecessary artifact which turned out to be the reason for slow shutdown).