Thank you for the quick answer. That opens a followup: Which hexbug parts are legal?
Some of the parts are basically the same, indistinguishable from VexIQ
Some are equivalent, just made in different plastic (other colors, translucent)
Some are a pretty natural extension of the set - more variations of pins and idlers, for example, or even the spider turntable.
Some are completely odd, like spider or strandbeast legs.
So far, we're keeping all HexBugs parts separated to avoid contamination with those almost indistinguishable parts, but, as an example, my kids claim that the black plastic is stronger and used the black pins from VexIQ trophy before. And those pins from Spider are so tempting....