One idea that comes to mind is the slow downward trend being restricted to the first half or third of the empire's history as the original nobility expanded to meet bureaucratic needs for the territory they ultimately claimed, then fluctuating over time rather than having any hard trend. This is to respect more realistic patterns of inheritance, as the underlying function of the degradation is that the bloodlines are thinning in the first place; once the nobility is reproductively insular, it should be approximately static.

Another thing that comes to mind is the idea of an individual with the same draconic bloodline in a number of degrees intersecting with them, being simultaneously a historic Sorcery bloodline, a Half Dragon, and more marginal things like the old Draconic template or 3.5's Bloodline mechanic of the same individual dragon across the centuries of her life (for the sake of a bit of variety), being an inheritor of a truly staggering amount of sheer power... That's genuinely Draconic rather than typical sorcery, and having a pile of issues with instructors as a result.