4 1/2 + years ago after receiving my first KITAP, I received both my KTP-OA and SKTT from the Catatan Sipil office in DKI Jakarta : from memory, I was not charged any fees for either document nor do I remember any explanation from the officials at the Catatan Sipil office about why an SKTT was issued to me. During the past 4 1/2+ years, no government office has requested to see my SKTT, not even the Immigration office in Tangerang when I transferred my residency from DKI Jakarta province to Banten province.
However last week when I visited the Catatan Sipil office for city of Tangerang Selatan to convert my paper KTP OA into an e-KTP, I was given a list of personal documents for which I needed to provide photocopies and on that list KTP and SKTT were listed; so I informed the officials at that office that 2 years ago when I obtained a new paper KTP-OA from the same Catatan Sipil office for city of Tangerang Selatan, I was told by other officals at the same office that I did not need to receive a new SKTT issued by that office because I am a KITAP holder with a SKTT still valid from DKI Jakarta; last week the officials agreed about no need for a new SKTT to convert my paper KTP OA into an e-KTP. During that visit, I did not ask if I would be issued a new SKTT when I renew my KITAP in 3 months.
If the law states that for KITAP holders, only the KTP-OA should be issued and not a SKTT, then probably I will request that a statement in writing be issued by a high official at that Catatan Sipil office to avoid any possible problem in the future with other confused or naive government officials...