My first attempt at a mod, so hopefully it turned out okay.

General

Tweaked the stack sizes of certain items.

• Expanded on below. Added a JSON config file.
• Simple String-to-Integer mapping.
• Key "MAX" alters the maximum allowable stack size.
  • Changed from Minecraft's 99 to 256 (by default).
  • Cannot be modified via the ModMenu (yet).
• Additional modifications can be made via the ModMenu interface.
  • Will only consider 'stackable' items (items without durability).
  • Currently uses internal item names.

Stack Size: 1 → 4

Food/Drinks

• Cakes
• Soups/Stews
• Potions (Standard/Splash/Lingering)
• Water Bottles

Mobs

• Horse Armor
• Saddles

Transportation

• Boats (Standard/With Chests)
• Minecarts (All Variants)

Utility

• Banner Patterns
• Beds
• Enchanted Books
• Filled Buckets (Water/Lava/Milk/Powder Snow)
• Goat Horns
• Music Discs

Stack Size: 16 → 64

Food/Drinks

• Honey Bottles

Mobs

• Eggs (All Variants)

Utility

• Signs (Standard/Hanging)
• Snowballs