Is this too much or not bad? I plan to keep my recovery keys in four separate locations, a brand new flash memory from Huawei, a brand new WD External hard drive, my book with a strong cover and my wardrobe, in my wardrobe you can't easily see it because its always dark in there, I use my torchlight to carve those words in there and its even written on the top inside the wardrobe, I tend to keep it this way for now till I can get a Nano X.
Well, the purpose of having a backup copy of all your keys, passwords and etc... is just something to help you recover in case you've lost access to it. Your idea is great and I think it was just you who could think about hiding them in the wardrobe. But I think it wasn't necessary, at least having two copies could be enough, written on paper and hard drive.
Thus, if you are using a hard drive or USB memory card just be sure you never use it for other purposes. It should be just a key keeper, nothing else otherwise this might be a reason why you lose control of your account.