It doesn't look like anyone has done a lot of work on a TAS of this game in the last five years.
The good news: Legaia really got broken in 2018. A number of major sequence breaks and minor skips were found, and there's a lot of potential.
The bad news: The most interesting category / fastest completion of this game requires save-anchoring for Incense purposes, and based on reading of the rules, that subjects a run seeking publication on this site to higher scrutiny for publications (again, if I interpret them correctly). Specifically, it requires repeatedly reloading a save file that exists before timing begins. More on this later.
The main idea: The consumable item Incense stops random battles. More importantly, when it wears off, a textbox appears that states that "Incense has lost its effectiveness". If that box should appear on the same pixel as a loading zone or a cutscene trigger, the former overrides the latter, allowing you to skip cutscenes, some bosses, and go out-of-bounds in other places.
The problem: Incense can't be obtained until after Xain, which is roughly 35% of the way through the game.
The 'solution': If I have two save files, A and B, and I use Incense in File B then load up File A, the Incense continues to work because the game doesn't scrub step counts and Incense step counts between file loading.
With this finding, it's now possible to complete this game in just over 4 hours. Even the any% run without transfers is completable in about six and a half hours.
Why is the "New Game+" run faster? Apart from not having to worry about any random battles for the entire game, Drake Kingdom is broken. We can repeatedly re-acquire Terra the Wolf from Snowdrift Cave and take advantage of the fact that a death with the Wolf in the party counts as a 'win' for purposes of allowing us to advance the plot. This means that the number of enemies that have to be defeated in the game is 3: the Red Piuras needed to advance through the training grounds sequence in Snowdrift Cave to activate the Infinite Terra glitch. It's also faster to use the Point Card on Caruban rather than waiting for him to KO you. But still, no levels, no grinding, no monotony of long, drawn-out cinematic battles....
And it's probably a borefest to the average viewer since the game is "skip cutscene, die to boss, skip cutscene, die to boss, repeat until you die to the final boss", so I am less than convinced it'd meet the entertainment criteria for 'Moons' publication. Still, I'd like to see this done. I'm willing to help out where I can, but I have zero TAS knowledge or resources.
I probably forgot to add something here...