Spirit Island · Board game rules
Do you still do the exploration during setup on the thematic board?
Quick answer
Yes, the Invaders still Explore during setup on thematic boards; this is not changed by using them.
Details
The thematic boards are an alternate map layout for experienced players, but they do not alter the core setup sequence. [p.23 — Thematic Map] describes them as prioritizing theme over balance, with different art and land clustering, but does not mention any changes to the setup procedure itself.
Setup proceeds normally: you still follow all standard setup steps, including having the Invaders take their initial Action at the end of setup. [p.6 — Invaders' Starting Action] states "To finalize the Setup, the Invaders take an initial Action. Reveal the top card of the Invader Deck. The Invaders Explore in that land type."
The thematic boards do have some setup differences—such as fixed relative positions and some overlapping lands—but these are layout matters, not changes to the sequence of play. [p.23 — Thematic Board Setup]