Well I will say this too, and that will be it from me on this topic. I completely see and agree with your ideals on this topic; Hence the reason I have not used either of those methods on MY rado. My rado only gets the best and NO short cuts, all Belltech and new.I know it was done in the past by old school hot rodders when there weren't any companies making lowering springs. Just because something was done in the past to get by because there was no alternative doesn't make it smart today. A heated spring will fail over time, the life of a spring that's been heated is significantly shorter than one that hasn't.
You're right though, you might get lucky with a heated spring and not have any problems. Then again, it might crack where it's heated and fail one day when you're driving down the interstate. It's the suspension to your vehicle, and isn't worth taking the chance IMO. Cutting a spring isn't really ideal either, but that's mainly because it changes spring rates and isn't good for a vehicle that you want reach it's full handling potential.