What we fixed in the mod:
Edge Crystal Placement: Added adjacent base block search (findAdjacentBase). When your crosshair hits neighboring grass/ground on an edge flick, the optimizer detects adjacent obsidian/bedrock and executes the placement.
Placement Under Blocks / Ceilings: Removed the strict legacy 2-block air clearance restriction. It now only checks entity hitbox collisions, letting you place crystals smoothly under overhangs, stacked blocks, and roofs.