Be careful with that confidence.
Suppose you generate a complete one-time pad, by measuring motion due to heat, or electrical noise from a gate, or even lava lamps at Cloudflare. A pad large enough so it never repeats. Not 256 bits but big.
There may be a day, when that key can be broken down to a simply set of factored chunks.
Here their algo appears to struggle because its [classical-chunk] then [quantum-factor-the-chunks], the quantum part doesn't do the heavy lifting, the classical part does. Fail to get those chunks and you fail to factor them. Perfectly break down those chunks, then all manner of factoring methods can work, not just quantum ones.
But there was another science story recently, an experiment that stopped a magnetic spin by heating it. Implying that the chaotic motion of heat contains the same component of that spin, i.e. not a random system at all, just a complex sum of many chunks that appears to be random, one of which was that spin component.
And so your 'random' key, generated from heat, would have an underlying pattern to it. A pattern you can ultimate identify by a *working* chunking-factoring-chunking-factoring approach.
You could wake up one day, to find your random private key is not random.