Interesting write-up about the challenges of tackling this kind of issue when building materials and construction have no standardization that many gutter guard products rely on.
One thing to consider in developed countries is that some products slide under the first row of shingles and may void your roof warranty... then again most of us around here like to do that sort of thing with our projects, albeit with less expensive investments than our houses.
It seems the only real solution is to ensure the product has no real holes or openings, like certain fine mesh products that have holes only microns in size. Again, it seems the real problem here is standardization and it presents an interesting entrepreneurial opportunity.