Super-habitable planets and volcanism?

[stevebowers]

The planet Seattle is currently the largest SuperGaian that has a complex biosphere in OA. With a mass of 7.5 Earths this is on the large size for a planet with plate tectonics, but it is much less dense than a planet with an Earth-like composition, so the iron core must be a much smaller fraction of the whole. Perhaps this factor has allowed the tectonic activity to persist.