On 1.14.4 running Forge 28.0.9 (Have not tested with other versions) this mod seems to be broken. I am playing survival so I'm hesitant to throw any more resources at it (brand new world, starting from scratch) but at least with regards to the stone hammer it's just mining 1x1. Another user has noted the same with a diamond hammer.

Ugh, my apologies, Twitch has them ordered stupidly and I just picked the one at the top of the list (which appeared to be descending) thinking it was the newest. Guess they were expecting leading zeroes or something when they programmed their sorting. I'll give that a try tonight

So unfortunately that doesn't seem to have done it. Happy to be running the latest Forge of course, but still rocking 1x1 mining on 28.0.45

Edit: Or not... it seems to be hit or miss. Do the tools have a chance of not succeeding?

Edit 2: Okay so I think I know what's going on now. It seems it doesn't like water. If the blocks are underwater it just does 1x1.

I think you must have missed my edits. Seems to work okay unless the dirt is behind water.

yeah, gmail doesn't show those.
Within the water, I can test this

Gotta love those edge cases. Would you prefer that I close this and open a new issue with a relevant subject and without the extra details?