I was trying out Rumble on this patch, and I found that he has a weird interaction with his harpoons. In the patch notes it says, "If Rumble overheats using Electro Harpoon, he’ll always be able to fire while silence as long as he has 1 charge (same as live)." That's correct, but I found that if you overheat with just one charge you can still use the harpoon even if you didn't overheat using the harpoon. I was at two charges, and I shot one. Then I used the scrap shield and flamespitter to overheat, but was still able to shoot one harpoon a one charge. I was not able to shoot the harpoon when it was at 2 charges however. I am not sure if this is the intended reaction.
As a side note, I tried buying CDR, and it did not affect the harpoons. I think this was intentional, but I just wanted to check.