Hello, here is a simple tutorial for you to increase “Game Speed” more than 4X.
It is very useful for you to test your mod or build a custom building.
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Unzip your “stonehearth.smod”
(For example, C:\Program Files (x86)\Steam\SteamApps\common\Stonehearth\mods)
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Find this path: mods\stonehearth\ui\game\widgets\game_speed
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Open “game_speed.js” with your text editor

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Find this text:


The four mode correspond to the four types of game speed,
DON’T change the speed of ‘PAUSED’ and ‘PLAY’.
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Change the number as your wish

I double the speed of ‘FASTFORWARD’ and 'SPEEDTHREE’
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Open the game
I don’t know how to make it as “.smod” file. Someone can provide me a tutorial?
You simply make it a .rar file or .zip and then rename the extention to .smod
Also you cant do changes unless you reapply it to the original location so After Step 5 you need to rezip the file in the right location and then open the game
Interesting idea. 
The usual way (but not toggleable on runtime) is to add this to your user settings:
"simulation" : { "game_speed" : 1 },
I love to use it with 0.25 or 0.5 speed (so slow-mo)… xD
Unfortunately, to convert this to a mod, you’d have to override those files, since mixintos don’t work for UI files =(
Going to add a warning here: increasing the speed will have a negative effect on performance. The faster the game runs, the more calculations the CPU has to complete each real-life second, which can cause “idle Hearthling” issues in game as the UI gets ahead of the CPU. Make sure you have a powerful enough CPU before doing this.