I'm just going to dump a few more ideas here:
A flower that turns mana-infused materials back into their original material, which costs even more mana
A rod that lets you have some sort of spectator mode? "rod of the hollow earth"?
Totems which you can put runes in, which provide an area of effect around them that does something based on the rune. The rune would be consumed after a while.
"Edicts": sort of like claimed chunks but cooler, you would be able to protect an area from being destroyed by mobs and even other players for a hefty mana cost
Mana lodestone: Infusing a lodestone with mana and making a compass with manasteel instead of iron lets you make a mana lodestone system. The compass will tell you the exact distance to the lodestone, and sneaking will create a beam of shimmering mana a short distance away, which will appear for every manasteel compass in your inventory. Maybe you could consume the compass to teleport back, sort of like an early-game version of the Eye of the Flugel, but worse because it requires using up materials
Infusing a bottle of enchanting to create a bottle of thunder, which strikes lightning where thrown but more valuably can be given to a Teru Teru Doku to start thunder
A functional flower which halts tickspeed in a large radius around itself, letting you use blocks for builds that would otherwise change over time
A functional flower that prevents PVP in an area (only direct pvp, you can still Key of the King's Law someone and stuff like that)
A flower which clears effects nearby
A rod that can trigger redstone and interact with blocks over a long distance
Corporea crystal cube matrix: click it to request all of the items in the matrix at once, useful if there's a recipe you do a lot