R. Kapach discusses this at length there, but here is my translation of the first bit:
And I have seen those whom desire has brought them to the point of imagining in these words of our teacher [Maimonides] that the entire punishment is that they will not merit eternal life, but there is no active punishment and no burden or pain, since he wrote "and is destroyed like an animal", and there is indeed no punishment for the soul of an animal (and the soul of man in his understanding does have?).
And this imagination is a mistake, and even a sin to thread it in the words of our teacher, for he already wrote earlier in Chapter Three Law Fourteen "rather they are cut off and destroyed and judged for the magnitude of their wickedness and their sins for all eternity". Meaning to say that the cutting off doesn't save from the strict punishment whose essence we do not know, and there is no asylum in death.