The colonists are paying a land value tax in exchange for (protected) possession of the planet. Forfeiting the planet to avoid taxes makes no sense in this context. If they really don’t want to pay taxes and are fine with leaving, they could just leave and stop being taxed; no need to attack anyone.
Who’s stopping them from simply just staying at their planet, doing whatever they want, while not paying tax?
Who’s stopping them from simply just staying at their planet, doing whatever they want, while not paying tax?