Initials are not necessary in Signaturit because all of the data is recorded in the audit trail and certified by the Official Time Stamping Authority. One signature is enough.
Once the signing process is finished, all the data and information (time stamp, geolocalization, history, status, mails, IP, etc.) is stored into the audit trail (or evidentiary document) to guarantee the integrity of the data, and that nothing has been altered starting from a specific point in time.
That means that with one signature, the whole document is sealed and encrypted to reinforce the security and prevent any type of fraud or manipulation.
Signing several pages of a document or stating the initials in each page is only used in the classical paper signature, where pages can be added or manipulated. That way each page is secured. However, in the digital signature, only one signature is enough to guarantee the integrity of the whole document.