Does manumission (*'itq*) resulting from inheritance apply only to the inherited portion for minors and the insane?

Primary text

If a minor or an insane person inherits a portion of someone upon whom manumission is obligatory for them, the manumission applies only to that inherited part and does not extend to the rest of the slave. This is because if manumission does not extend to the whole for a legally competent person, it is more appropriate that it does not extend in their case.