why not to add Heyzapp? or some other video mediation platform. For me adding only 1 video networks sounds like wasting of your and our time. If someone using video ads it using Vungle, Adcolony, Applovin, Unity Ads - so there is no case to support only few of this networks - you need to support all of them or add support for some mediaiton platform which could handle then all this networks.
As fyber now merged with Heyzap - and heyzap have adapters to Appfigures - I think Heyzapp currently is best candidate to integrate. Also I think this guys will be interested in this.