Every event, no. But she did once, and so did Tiny Asa. (In fact, I think it was both of them in the same year for one of those events.) Search between CosForce, Cosfans, Cosplay Universe and AGA, check which girl is doing which, go for that one.
You buy the regular ticket for the event (plus the planet ticket to Taiwan, if you're not from there), + the ticket for the VIP access (50 USD last I checked), + whatever potential service you want to have from the VIP girls not included with direct VIP access (the VIP ticket already includes a lot of shit, you just miss on them sitting on your lap and the motorboating/neck kissing). Being handsy is a BIG no-no, but some girls are cool with it.
If you're trash tier unc status, all you'll get is the VIP hidden treatment inside the reserved booths. If you're hot enough to pass for an OP anime protagonist, there's a miniscule chance you'll be freely upgraded (evidently, up to you, since you'll be in front of thousands of cameras and not everyone can take that press) to piece of meat of the day and be groped/grinded/whatever by several of the girls in the main stage, hands tied behind your back, while a bunch of sad simps watch with "that should've been me" written on their faces.