Comment by debian3

Might sound strange, but you could always contact @olesovhcom on Twitter. He is the CEO of OVH and he made change to their DDOS filter base on what we reported to him. He is always interested in improving is offering. But that was maybe 5 years ago, now maybe he will put you in contact with someone else, but back then they were actively looking for feedback to improve their filter.

Edit: you could always contact their support as well. Fighting DDOS on your own it's an expensive/difficult battle. But their DDOS filter is fully custom (mostly Asic and some Arbor as well).