you have to have a full stack of for example magma in your inventory, the rest of your inventory is filled so that any additional blocks go into the pickaxe. then if you throw out less blocks than one stack and and less than there are in the smallest stack inside the pickaxe your stack gets filled up again but the amount in the pickaxe doesn't go down. for example I have 3 magma in the pickaxe, You throw out one magma from the stack with q then the stack fills up but there are still 3 in the pickaxe. this works with all breakable blocks that land inside the pickaxe.
Minecraft 1.20.1
Forge 47.4.16
Citadel 2.6.3
Alex's Mobs 1.22.9
you have to have a full stack of for example magma in your inventory, the rest of your inventory is filled so that any additional blocks go into the pickaxe. then if you throw out less blocks than one stack and and less than there are in the smallest stack inside the pickaxe your stack gets filled up again but the amount in the pickaxe doesn't go down. for example I have 3 magma in the pickaxe, You throw out one magma from the stack with q then the stack fills up but there are still 3 in the pickaxe. this works with all breakable blocks that land inside the pickaxe.
Minecraft 1.20.1
Forge 47.4.16
Citadel 2.6.3
Alex's Mobs 1.22.9