In an effort to keep my base neat and compact, I've been using smart/programmable splitters. These work fine, so long as the whole line is moving, but if something on the line backs up it can also prevent other, not overloaded materials from moving (current issue is with iron and steel ingots).
It would be awesome if there could be either a machine or a setting that would allow overflow to be automatically destroyed, instead of piling up on the conveyor.