It's a nice idea, and certainly has some advantages as you point out - error correction and not requiring the wordlist to convert back. However, OP has said he wants to use this technique to memorize his wallet/private key/whatever. I've pointed out above that this is generally a terrible idea, but if you are going to try to memorize your wallet (especially over a long period of time), then you want something that is as easy to memorize as possible. Using your technique for a WIF gives you 52 words to memorize, as opposed to only 12 words with a BIP39 seed phrase, as well as requiring you to memorize if individual words are lower case or upper case, which all adds up to something exponentially harder to memorize and exponentially easier to forget.