Yeah, a unified baseline radar API would be really nice. If it does all the basics well, is nicely implemented and configurable for specific features, that could help other modules a lot imo. Radars are just so complicated, even getting the basic right seems to be a big challenge for the developers.
Honestly, I wish Heatblur or Razbam would license their Radar APIs to other devs or DCS in general, those two seem to have the best radar models. I know at least HB is developing general radar-framework with the F-4E, which is gonna be transfered to F-14 and Viggen in the long run.