Looking on the internet deeply has found these results:

should be blazingly fast is the most popular phrase on the web.

should be blazing fast 16,460 results on the web	should be blazingly fast 19,710 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Vermiculite, a blazing fast dissolving of the body?	How can that be blazingly urgent, vitally important?

should be blazing fast

16,460 results on the web

should be blazingly fast

19,710 results on the web

More popular!