I believe that in the last thread, or another forum, I commented that I built my own carbon fiber based rack. It has held up for 2 sub-800K rides. This iteration of my rack weighs in at 600 grams.
When I first started searching for a "universal rack" to fit my first bike camping adventures, I didn't really know what would meet my requirement for the gear I would be carrying. I am a firm believer of using a dropper post, so this pushed me away from using a large seat-post bag.
I started out my first few 2-week long bike camping adventures using a modified 30-year old blackBurn rack fitted with left, right and top panniers. I learned to hate riding a bike that weighed around 60 pounds total, when I rode my first bikepacking BKT event.
Over the past few years, I migrated to running dry-bags, with my tent on the front, below the bars, and a frame bag. I have been able to reduce the weight down to around 46lbs, (food and water capacity = big weight variance. )
From my perspective, every bike camping adventure I ride, seems to have different packing needs and weight, so I have self determined that no single "rack set-up" will ever meet a specific ride's requirements.
I believe that most of the bikepacking rides in the US and Canada have been converging on around 800km or 500 miles, in order to accommodate riders who have at most a week to get out there and ride a "published route" or participate in a mass start event. It becomes a different ballgame for rides like the "Tour Divide".
Therefore, if you want to sell racks, the market that Tailfin and other more application specific rack builders participate in is still a very small market. (To me, Tailfin is too heavy, and costs too much, but is very durable.) I spent about $60 on off-the-shelf carbon fiber plates and tubing, spent some time on my mill machining the parts, added some epoxy and rivets, and put mine together.
My winter plans to build a few more experimental racks has been delayed because my next order of carbon plates and tubes was lost and refunded, and to place the same 11-11 order is costing an additional $50 over what I originally paid, and I can't get an of the current coupons to work with my next order. (venting)