When I create a new key, it will return seed phrase with the same last word every time.
This should be caused by keybase.go#50,

typ := cryptoAlgoToByte(algo)
secret = append([]byte{typ}, secret...)

secret[0] is invariable, when BytesToWords, because of secret.length = 21 and words.length = 2048(2^11), the last word index = f(secret.bits[21 * 8-11 * 15]) = f(secret.bits[3]) = f(secret[0].bits[0,2]),is also invariable.

typ := cryptoAlgoToByte(algo)
secret = append(secret, []byte{typ}...)
will avoid it.