When it comes to the TS100 the power supply you’re using matters more than you’d think. I have no problems with 10awg wire on mine and the 8awg wire wasn’t too hard either but I mostly just removed the old unneeded 8wg stuff so I haven’t soldered with it a lot.
Damn, that was hard to find to be able to quote the voltages available. The kit I bought included the 24v power supply so I haven’t had any issues with getting my iron hot enough so far, but it seems that when you get the lower voltage supplies it will struggle to stay hot enough for larger wires.