What is the legal status of changing a condition applied to a previously established manumission (Tadbir)?

Primary text

If a previously absolute (unconditional) Tadbir is made conditional by the master, it becomes conditional, assuming the revocation of Tadbir is permissible. Conversely, if a conditional Tadbir is made absolute, it becomes absolute in all cases because this constitutes an increase (addition), which is not prohibited.