TL;DR... Base Metals and Modern Metals both add a lot of metals to the game, but with existing mechanics, you're stuck to using only Iron to manufacture buckets. This mod ties into Base Metals - and Modern Metals, if its installed - and adds buckets made of those materials.
In the MMD Core Mods - BaseMetals and ModernMetals - there are a lot of materials added. But you still need to use Iron to make the buckets - changing this is possible, but why stick with just Iron as a material to make buckets from?
Here is a response - all the "metal" type materials added by BaseMetals (and, optionally, ModernMetals) are able to now be crafted into functional buckets. Right now these are, basically, just custom versions of the bucket everyone knows but we're working on some ideas to change this - buckets that melt if exposed to the heat of Lava or have limited durability because the material doesn't wear well.
While we don't have those features, yet, they will show up as other work on MMD Mods progresses. And yes, sadly, as with a lot of MMD Mods, BaseMetals is required for this mod to function.