I fail to see whats with the hype and hysteria surrounding Quest Diagnostics. They are no different than any other DHHS-certified lab. They are not some rogue supernatural entity thats going to come down from some uncharted planet in outer space to strike terror into the hearts and minds of those passing through their doors.
There are lots of posts in the DT forum of successful synthetic subs at QD.

TestSure is just QD's brand name of their validity test (creatinine, pH, S/G, excessive nitrites, high chromates, pyridine, glutaraldehyde, and surfacants). No big deal here.

You can perform these same checks on your synthetic if youre unsure of its efficacy. Do a Google Search for "drug adulteration test kits".