Davis really thought about it.
If he was going to use Tia's divination, then it would've been better to just take the long route. To head back to the Eternal Twilight Shard Region will take around two to three months, and from there, traversing to the Shard Region Shirley was in was going to take three to four months.
But in the Shard Continent, it was around fifteen days.
Fifteen days compared to six to seven months, the answer should be obvious.
However, it wasn't obvious since the danger levels in the Shard Continent were extremely high.
Furthermore, they couldn't travel to Bylai's Shard Region without heading back to the Eternal Twilight Shard Region again.