I'm a bit conflicted on starting level / XP value. On the one hand, I don't want to build too many low-level dungeons on Voltager, since the mainland is the primary attraction of the setting. Wilderness adventure more-or-less entails 5th-level for good survival odds, though, so I don't want to hold XP numbers down for long. On the other hand, having played in a campaign that started at 4th level, it felt too powerful in the beginning. Two webs and two sleeps a day is great, and then you pull fireball soon after (with a little luck or a scroll). I'm sort of thinking something like 7500 XP; close enough to 4th that folks will level into it after a decent treasure haul (or already be there for thieves and clerics), but with a gap before they'll probably want to go deep into the jungles. Good level range to hop between frontier settlements for a while.
High-3rd also seems a reasonable fit for the degree of difficulty that has been baked into this fully-operational
Fortunate side effect of 7500 XP: 6000 GP to spend on important low-level adventuring gear like Reserve XP and Restore Life and Limb castings.