Fabricated Leaf Spring Slider Brackets?

Has anyone fabricated brackets for their rear leaf spring sliders, rather than just welding the to the framerail?
It seems to me that you may want more adjustability than is provided when just simply welding them in place... Because, I assume, that if you need to add weight to the back, or subtract it, change springs, etc. it will change where the shaft rides in the slider... Thanks in advance!