Isn't cooking spices the same as cooking anything? I don't feel heat is as large a factor in curry making as some people make out, surely if you can't get extreme high heat -which could burn the spices- then simply cook the spices out at a lower temperature for a longer time.
In my opinion, how you cook the spices doesn't really matter, what matters is whether or not you are able to tell
when a spice is cooked sufficiently, either by sight or by smell, which involves technique, palate and to some degree cooking experience

As I have said before, in the early 80's there were an awful lot of small takeaways opened and they didn't use great big burners or huge ranges to cook on, just a bog standard kitchen cooker, yet they all had the taste and smell :
