Height-Locked Mining

A client-side mod to help with digging.

Behavior

The mod starts disabled.
Press X + ] together to toggle it.
While enabled, mining is allowed only on two horizontal block layers:
1. the y layer directly in front of the player
2. the layer immediately below it, representing the lower body.
Attempts to mine the floor or any other Y layer are canceled.
The two permitted layers are recalculated from the player's current eye position for every mining attempt.
Toggling the mode cancels any currently progressing block break.

The ] part of the shortcut is available under Options → Controls → Key Binds → Height-Locked Mining. X is the fixed modifier for this mod.

The mod is client-only; it does not need to be installed on a multiplayer server.

The following text message appears when you toggle the keybind.

Here's a video showcasing how the mod works: https://youtu.be/uXK5r0Y_8nc