For your research, know that if it was on offer then we would use it. There's often a substantial difference between price offered by OTA and direct with airline, and when you multiply that by 8 for our family, it ends up being quite a bit of money!!With many OTAs you can’t, they need to offer you a fare family up-sell, and a lot don’t do that for long-haul flight or meta-search traffic.
We’re actually debating at work right now about how many people would use it, so if it’s worth the development effort versus doing something else people would like.