Send me an note when you order next. I don't mind adding holes to arms. Just let me know how many. If you order some like that, I would appreciate feed back on how they work out for your intent.
Hmmm. What if I made a block adapter with a bunch of 5mm ports in it? You could attach it to the end of one of the arms, and than plug in the ghost stand arms into the block. Would that get the effect you are looking for?
XL arm is about 6" pivot to pivot, and the standard length is about 3" pivot to pivot. Here are some pics. I typically use both an XL arm, and a standard arm on the bottom pivot.
I 3d print all YetiStand adapters with my FDM 3d printer. Even when printing with clear filament, the part will not come out clear due to the FDM process.
You could easily tree off with dual arms, and knuckles to allow more than one figure per pivot on the detolf adapter. I don't want anyone's glass shelves to break, so I still recommend only one figure per pivot.