I thought I'd give this mod a try and I noticed right from the start there were some large UPS drops. Checking the debug screen, I saw this script regularly spiking above 1.5ms updates. I took a peek to try and see how the script works but couldn't immediately spot it.
On a sidenote, I tried playing with Hard Crafting and it was pretty brutal. I got overwhelmed on the first night as I was still struggling to get my iron and copper together.
The mod is balanced for playing with about 3 people. You could try playing around with some settings in config.lua to make them a bit easier :)
Thanks for raising the UPS drop issue, I've not encountered it myself but I'll see what I can see.