Although I have said this a few times, it bears repeating. When I start the game over on a new map seed, I will not build my HQ on the continent upon which I spawn.

My son and I built a huge castle not far from the pillars spawn-point. We quickly ran out of access to sources of ore on that continent. A couple of weeks later we found a nearby continent to the southeast, that not only had access to large tracts of meadow, forest, swamp, mountain and plains, it also had lots of iron & silver. If we had built our main HQ there we would have spent a hecuva lot less time shipping ore for refining. After repurposing a Troll Cave into a portal room, I found a very large semi-abandoned Draugr Village in meadow bordered by Black Forest with nearby swamp, plains & mountain. I restored all the buildings and built vegetable and animal farms, workshops, smelters, surrounding it all with an earthen wall. Due to the fact that I did a minimal amount of terrain alteration: only using a hoe to level a few mounds in the gardens; my son experiences no lag and FPS loss.
FPS loss plagued us at our original HQ because of the large amount of earth levelling done there combined with the large scale of the stone castle and building construction.

To avoid spending a lot of time transporting raw ore for refining, I recommend thoroughly exploring nearby land masses before devoting a lot of time and effort into major base construction.

cheers,
Quando Omni Flunkus Moritati (When all else fails, play dead)