33mg per ml isn’t outrageous, and if achievable, is a useful potency, but based on my experience it is unlikely to have been achieved by direct extraction. 2mg/ml sounds like direct extraction.
obviously much higher dosage can be achieved by making an emulsion.
I infuse THC into MCT at 33mg/ml or 1g/fluid ounce for retail & medical usage. I’ve not explored doing this infusion directly, but suspect the solvent losses to the biomass when trying to hit 33mg/ml would be an issue. 10mg/ml seems more doable. I do plan on nailing this down at some point as enabling technology.
As an example: using 1 gal of ethanol to extract 1 lb of 20% flowers gives a maximum theoretical tincture concentration of 90.8g in 3785mls or 24mg/ml. With ethanol you can pass the same solvent over fresh biomass several times. So achieving 100mg/ml tincture without evaporation is doable. The same technique can be used with gylcerin, although I don’t know how much it helps. I would wager that the glycerin tinctures I’ve tested have all been single pass.