Almost nobody grows pure ruderalis for flower, since it is small, low in THC and quite plain. Its value lies in the autoflowering trait, which breeders cross into stronger photoperiod lines to create modern autos. Ruderalis content is sometimes mentioned in the autoflower lineage notes at https://budweedseeds.com (https://budweedseeds.com), and a higher share usually means a hardier but less potent plant. I find it a useful clue when choosing between two autos that otherwise look similar.