I have recently completed a build of a Titanium Salsa Warbird that I plan to use on lighter tours with bikepacks and also to replace my current work commuter bike. Because I got carbon drop bars on it I could not put my favorite Ortlieb on it but I did repurpose one of my other bags that actually ended up looking rather nice on this setup. I added Revelate Designs Cuben Fiber Freshroll to it. I have checked out the Revelate web site and also found this handlebar bag that would definitely qualify as LIGHT per your request:
https://www.revelatedesigns.com/inde...r/EgressPocket
I haven't taken a photo of the bike with it yet. I only managed to squeeze in two days or riding on the new bike before it started snowing ;-)
I will take a photo sometime by the end of the weekend and post it. In the meantime here is my new Warbird after completion of the build:
