The /help says it decodes only 3 specific lengths of hex strings, and it does that. The /help says it decodes only 3 specific lengths of base32 strings, but instead it's looking at all other lengths greater than 8 which are multiples of 8 without containing the '=' padding character, to see if they match the pattern of base32 encoding.
Or is this decoding of all these additional base32 lengths what /help means by 'Google Authenticator' format? The /help mentions that as a 4th way of handling keys, but I couldn't find a 4th way beyond $utfencode($remove(decoding hex,0x00)), or decoding base32, or literal text.