DaVice
4
When you say Single Player, are you talking about playing by yourself (in a clan of 1), or are you talking about a single player saved game? If it’s the latter, remember that your machine is acting as both client and server. If it’s the former, see below.
Your client only knows or cares about the stuff within render distance, so whether you or another player has built something in another area of the map, your “client” will not lag because of it.
If however, there are 40 players who are all online and all have 4k builds, plus thralls and placeables, the server may struggle to communicate to those 40 clients what is on each of their screens. If the server is struggling, it can feel the same as client lag, but it is out of your control.