I found
this suggestion interesting. What do you think?
I think it would be helpful because even without its self-imposed limits, it is easy to control with a humble cobblestone floor, yet it would have quite significant uses. You could be given one block in a survival map and acquire as much dirt or grass as required. In addition, it would be helpful for any wanting to live in the sky or nether. In any case, it's definitely an incentive to find a mushroom biome.
If/when I start the mod-coding, I might create this as well. Of course, the conjuration part of the mod would break needing to find a mushroom biome, but at least you wouldn't have to manually conjure each block of dirt you desired that wasn't provided.