I am surprised iceladic folks havent designed heat shielded ceramic or silicon tile covered volcano emergency pods that could be at shorelines and released, or in backyards/businesses.
Some may be able to travel on a flow, some might get embedded, but thats the risk you take. Could have emergency beacons/radios so people could locate it and posibly get to them.
Even a large event is not big enough to require a mass evacuation of the island. Since events in this area can continue for a long time, it could eventually lead to relocating the capital, which is located far from the island’s center, but 25 miles from the location of eruption.