When you fully EVAP the iso it's will be that hash then adding what like 2 ounces of anything like vodka to turn it back to liquid and pour into dropper bottles. One dropper full think will be good to use. Got good tolerance
You still want to use the highest proof alcohol you can to fully dissolve the hash and not waste any. I’ve done it with 100 proof vodka and it worked well.
As far as quantity of alcohol to add back that is what determines dosage and it will depend on the potency of the extraction you preform and your tolerance level. Some people might make it stronger or weaker to be able to dose differently. How much your dropper holds will also change the dose.
I was mixing up some vials of liquid LSD a few years ago and quickly found out that different droppers hold different amounts and make different sized droplets. This totally changing the dosage. The same thing applies with tinctures.