Haste has inconsistent behavior with different tools and efficiency levels.

How to reproduce:

Make a circuit like the one in the screenshots:

This circuit will start to fill the other hopper with items once the first block is broken. once the last block is broken, it will lock the hopper, stopping the item movement.

No shovel + efficiency 5 test because shovels already instantly break dirt with anything above efficiency 3. assumed to be 9 because stone with efficiency 5 + haste 2 is also instant break.

From the results: it seems Pickaxes work fine with haste, while shovels aren't affected at all, and axes aren't affected with high levels of efficiency.