Elvee listens to his recordings of what Marlo was singing, compares it to his reconstructions, makes notes on how he can do better next time.
He wants to know everything about Marlo. It's like he feels about the fall of civilizations or about long-lost Force cults or about Asha; he wants to know, he wants to understand, he wants to have all the information lined up neatly and organized and put into a system, he wants to make predictions and test them, he wants to contemplate the beauty and complexity of his person--
They gave him the ability to program. He's good at covering his tracks. The Jedi Temple is not as good at computer security as it should be. Elvee downloads Marlo's school records and his health records and his Master's reports and the results of his Trials, everything he can find. He doesn't have time to read through them all now, but he will later, and they'll be there when he needs them.
Droids can control how they file things, to a degree; there was no point in removing the ability, most droids see no reason to hide things from their masters. Elvee carefully places the information about Marlo somewhere obvious, but hidden enough that whoever's mind wiping him thinks they've found all his secrets. He hides the recordings in "music," next to the information about epic poetry and obscure philosophical thought experiments; he fills "music" with musicoethnographies and Thandyusian whalesong.