Even 151 proof everclear (75.5% ethanol) is almost 25% water, meaning that there are at least 3 problems with using it.
(1) Only 75% of the volume used is real alcohol, so even if that diluted ethanol can dissolve as well as pure ethanol, it can dissolve a maximum of only 75% as much, volume for volume.
(2) Diluting ethanol diminishes it power to dig cannabinoids out of herb, just like diluting alcohol reduces its painful effects on your tongue.
(3) Even if all the alcohol evaporates, there will still be a lot of water left in the tincture. Too much reduction could result in a water tincture with settled out cannabinoids.
(1) Only 75% of the volume used is real alcohol, so even if that diluted ethanol can dissolve as well as pure ethanol, it can dissolve a maximum of only 75% as much, volume for volume.
(2) Diluting ethanol diminishes it power to dig cannabinoids out of herb, just like diluting alcohol reduces its painful effects on your tongue.
(3) Even if all the alcohol evaporates, there will still be a lot of water left in the tincture. Too much reduction could result in a water tincture with settled out cannabinoids.