That's great except we aren't talking about traditional handlebar bags in the first place.
While I tend to look at such purchases as learning experiences I do regret buying the Blackburn system because it was way over built for the purpose and the quick release mechanism ill suited for the task. So perhaps that experience might give another something to consider.
I like the Revelate design for light weight and simplicity but waffle a bit at the price. I admit I am frugal. Others may not be. If price does matter it's pretty easy to analyze and replicate that design via DIY.