Wow that sounds interesting to say the least!
It is, I want to stress
as intensely as possible that people have died on less than a single milligram of MDMB-4en-PINACA. ~800ug Is often considered to be the point where death might become a possibility. I found threshold oral doses around 10ug (remember, ug being micrograms, not milligrams). This is as somebody who is often eating 125-500mg of THC-O Acetate, which is ~125% the potency of normal Delta 9 THC. I first interfaced with spice because I used to live in Portland, Maine, in this ghetto where there's a huge spice problem. I was smoking 2g+ of rosin a day, and one day this spicehead fell through my bedroom window clean over the head of the bed I was asleep in, so I rolled out with a knife but immediately realized that he wasn't doing this on purpose, he didn't even know where he was! He had been grunting like a caveman and swinging back and forth on my porch railing, and eventually the screws came loose so he fell through the window. After that occurred, I figured "Damn, well this shit seems HEADY, I better try some" and I was pretty well connected with those who trafficked substances to the homeless community, so I grabbed some spice prerolls, and the first one I smoked felt identical to maybe 25-30 LARGE dabs, I'm talking at least 1-1.5 full grams of medical quality rosin straight from the dispo. Eventually, I grabbed a gram of MDMB-4en-PINACA, and it became ~40 tanks of vape juice (at 730ug/mL, most people do 1mg/mL but this is not a drug to take lightly), and I laid the remainder onto blotter, 2 sheets of 200ug per tab (WAY too strong), then 18 sheets of 100ug per tab (still strong but not as dangerous as the others).
For some reason, MDMB-4en-PINACA does not seem to desensitize me towards HHC nor THC-O, which are the other cannabinoids I've got on hand right now beyond trace amounts of THCa, THC-V, THC-B, THC-H, and THC-P. Those all seem to have a separate tolerance from MDMB-4en-PINACA and I can't tell why. I've also personally witnessed MDMB-4en-PINACA lead people into irreparable psychosis, and into death, in front of my own eyes. This is
absolutely not a compound to be taken lightly. It demands respect. If you are not comfortable with things like laying blotter, volumetric liquid dosing, reagent testing and melting point testing materials, you should probably avoid it. If you ARE however confident in those abilities, a single gram became 2,100-2,200 tabs as well as 40 full tanks in a box mod. It's unbelievably cost effective and unique, but much like the 25X-NBXX series, it demands respect and will harm or kill you if you do not come correct.
working on that. 
