FF6 Expansion Editor (FF6ExpED)

Just to be clear, vanilla does not let you steal but one per monster and Multi-Steal does not chance that behavior either; it does, however, let you steal more than one item per turn, which vanilla does not do (it only lies to you and lets you think you do, and simultaneously prevents you from stealing from said monsters on subsequent turns).

So this does not change that at all, but it gives additional steal slots and customizable rarity rates for each.  (PB increased the slots to 4 also, but the rates were still fixed, so this is even more customizable than we went with it). However, Leno did change the steal function to include a heavy dependence on the Speed stat as well, although I can't remember the exact formula he settled on, I remember that level was no longer the be-all-end-all.