TL;DR This mod adds a small variety of blocks and items to help reduce inventory management burdens and make automating certain kinds of farming easier. Most of it's OP nonsense, and various one-off silly things I've added to the game, not unlike Reliquary, though I've tried to avoid repeating any of my ideas.

A brief warning: This was a two week primer in 1.14.4 modding. It is a work in progress, needs MP testing, and continued support. If you find something wrong, please let me know.

Here's a list of the mod functions, in a nutshell.

Blocks:
Ender Keystone - Zip around the landscape using keystones to "blink forward" at your current axial bearing.
Interloper - Observer's evil cousin. Kills enemies when powered, reduces them to one health when it isn't. Doesn't work on bosses.
Lifeless Spawner - AKA "Spawner Template", an empty spawner waiting for an entity to spawn, using a Soul Tome. (see Items)
Condensing Hopper - A Hopper that uses space magic to smash weak rocks into strong rocks.
Expanding Hopper - A Hopper that does almost, but not quite, the polar opposite of a Condensing Hopper.
Enticing Prism - Makes fishing bobbers nearby tick 100% faster, additively (stacks).
Growth Pulser - Growable blocks nearby will get a growth tick every 10 seconds. Doesn't stack.
Ender Vacuum - Vacuums nearby items, while removing their gravity and collision to enable easy through-wall/floor farm collections. Also looks neat.
Mercurial Grindstone - Reduce the repair/anvil costs of an item by spending Mercurial Blend, or strip enchantments from items using books.
Frugal Anvil - An unbreakable anvil that reduces the repair and combination costs of items to a third of what they would be in a regular anvil.

Items:

Crystal Compass - It points the way to diamonds, emeralds, lapis, nether quartz and glowstone. It's probably the most broken thing in this list.
Cubing Talisman - Anything in your inventory that can craft a 9:1 block of itself does so automatically, if you have more than a stack of that item.
Moderating Geode - Eats minerals while you're mining. Leaves a single stack of each distinct "thing" in your inventory.
Potion Belt - Holds up to 255 stacks of potions (which have a stack size of 1, so.. 255 potions at most). Leaves exactly one of each distinct potion in your inventory. Also keeps the empty bottles.
Quiver - Exactly like the Potion Belt, but for different types of arrows. Works with Spectral/Tipped arrows as well.
Soul Tome - Sock an enemy with it; if their health is low enough, you'll catch their soul and the book will be usable on a Lifeless Spawner.
Mending Ember - Equipment in your inventory with Mending is repaired directly from your experience pool rather than by collecting experience.
Enchanting Star - A mid game reward for defeating the Wither, yielding slow, but constant experience points.
Ethereal Mallet - A container you can open at will. Items in the container tick; you can stash all the mod's nonsense in it and they'll work.
Mercurial Blend - A weird substance used for crafting in the mod, but also a resource to spend at the Mercurial Grindstone to reduce repair costs of items.

Getting Started:
Craft Mercurial Blend (redstone dust + sugar + black dye (dye, not ink sac) + slime ball) and craft it with a Book, creating a Mercurial Manual. It's got everything you need to know, I hope.

Enjoy.

Mercurial Tools