The optional config parameters affect what happens when you jump into a mine shaft:
PercentDamage: affects the amount of damage you take when falling, which is normally levelsDown * 3 (default: 100 i.e. no change)
PercentLevels: affects the number of levels you fall, which is normally 3 - 8 but has some quirks (default: 100 i.e. no change)
PreventGoingToSkullCave: prevents a mine shaft dropped in the mine from taking you to Skull Cavern if you fall beyond level 120 (default: true)
SkipConfirmOnShaftJump: skips the confirmation dialogue when you click on a mine shaft (default: [b]false/b])
This mod now requires JSON Assets to run.
You'll need to install SMAPI to run this mod:
https://smapi.io/
Then place this mod in your Mods directory and unzip it.
Code is at https://github.com/aedenthorn/StardewValleyMods.
If you want to complain or ask for help or help me test my mods, you can visit my Discord server.
A list of all my mods for Stardew Valley is available at https://www.nexusmods.com/stardewvalley/articles/895.