Current Status
At first, I remember reading an article about 00-Raiser's extra hand which happens to fit 00 Quanta. The problem is that the hands are weak and can't have a solid grip when holding the sword (combination of ball-jointed thumbs and connecting fingers to the palm)
The reason I ask about the 00 Raiser's MG and Designer (from my previous post) is because I saw the manual that their peg is almost identical. I couldn't find my MG 00 Raiser and the other Designer Color (either Cherudim and Arios version) at that time.
Once I found my kits, I ended up using Arios' right hand. Slot the sword inside it and connect the peg to Quanta's wrist and ended up with this pic
Which is awesome
And can do multiple poses if I can have a tighter right arm to support the weight.
The problem is when you go to the other side which looks like this
And here's the comparison between Quanta's original right hand and Arios' right hand (with sword)
Now... once I got the order of new set of palms (GGInfinite or but a designer kit... which is an iffy), can I use a knife to cut the bulk and glued in the skinny peg? Would that work and not having to worry about the sturdiness?