AlsoTapered
Bluelighter
There is really no safe way to use any of these superpotent opioids.
And speaking as someone from Vancouver, carfentanil has been around for years now. Since at least 2019. It's definitely more common now though.

'Dose as small as a grain of sand can kill you': alarm after Canada carfentanil bust
Discovery of 42kg of opioid, described as 100 times more toxic than fentanyl, in Toronto home throws spotlight on dangerous and poorly understood drug
Looks like 2017 was the first major lab bust in Canada.
Carfentanil and the Rise and Fall of Overdose Deaths in the United States - PMC
It is widely believed that the 2018 decline in overdose deaths in the United States was attributable to a range of public health interventions; however, this decline also coincided with the regulation and decline in use of potent fentanyl analogs, ...

But apparently it's been around for longer.
I simply cannot fathom people choosing to make a controlled opioid. There are structurally novel but synthetically no more complex compounds known. Typical for me to reside on the ONE nation on the planet where they are automatically controlled.
But I feel that much beyond x10 morphine requires properly controlled dose units. When you get to x10000... well, the RANGE of x10000 because while all opioids have a potency range, those ranges appear to become HUGE when considering the super-potent examples.
Nice to see you back, sekio