How about an option to make veins finite, to encourage expansion to find more veins. Most other mods that have mechanics like this make veins finite by default.

I honestly not only support this, but want to add a detail to it:
Adding this option as a vein property. This way it would be possible to make some veins infinite and some finite. Maybe make it have a "min" and "max" property, too, and just roll between the two on vein gen. The infinite setting might literally just be activated by making a vein without these two properties