One of the key advantages of conjugated polymers, and organic semiconductors in general, is their ability to be solution processed on a large scale with high throughput and energy efficiency. Since the performance and functionality of conjugated polymers is a direct consequence of their multiscale morphology it is incredibly important to understand and carefully control the structure of conjugated polymers at all length scales. Towards this end, preaggregation of conjugated polymer solutions prior to deposition has been studied extensively by means of solvent quality tuning and solution pre-processing, as it can drastically improve morphology and electronic performance . However, many studies have been phenomenological, focusing on the tuning of processing parameters followed by ex situ characterization of film morphology or electronic device properties. Additionally, many such works fail to ascertain or investigate further the precise aggregate structure, instead relying on qualitative visual assessments of films or spectroscopic comparisons. While these studies have led to the development of high level design rules for optimizing performance, there is a lack of fundamental understanding regarding the actual solution state conformation and assembly structure of conjugated polymers. Furthermore, commonly used methods such as UV-Vis spectroscopy and ex situ film characterization give hints towards the polymer aggregation state in solution but they do not provide a clear picture. While small angle X-ray or neutron scattering (SAXS/SANS) can yield a detailed, quantitative description of the aggregation structure, the scattering profiles of D-A conjugated polymers have been difficult to interpret.