There's a new dupe glitch in which the last item in your items menu can be glitched (you can put any item in the last slot by dropping it then picking it up), to do so you need another item that must only be x1, you cannot have more than one of this item (if you have more you can just drop them and then pick them up after you dupe), now that you have an item at x1 and the item(s) you want to dupe in the final slot, you simply jump up, trigger shield surf ( x + a) and while you're mid-air, you hold out the item at x1 and the item(s) you want to dupe, they will drop and when you pick them up, they will be duplicated. Only bad part is taking away shield durability which may have issues, but this can be used to quickly and reliably get as much topaz and diamonds as you want/need for the run. I personally learned this because the dupe glitch using the bow was unreliable for me
A great sky island % category would be nice to run just like great plateau % in botw speedruns