I think the main issue is they just don't have enough examples of it. So it's mostly looking for more of it, hopefully with either new symbols or in different arrangements or with some kind of context clue.

There's a fun book about the translation of Linear B by Margalit Fox called the Riddle of the Labyrinth. It shows what what kind of volume of symbols is needed to account for things like if the writing is gendered or to account for different people's writing styles.