I figured it would be best to optimize parameters as much as possible on one front, and then from there, do batch samples of the most promising solvent at different concentrations and types of acids. Unfortunately, the lack of quality equipment means the sample sizes are going to have to be large enough (ie. expensive) to be able to quantify the results.
1ml (5g tobacco) is just about workable as a minimum - if have narrow, tall containers (clear ones are best of course); test-tube like.
Yes, a multifactorial analysis will be great.
Wrt veg oils, I feel a more saturated one will work best (most inert); but one that is 'light'. That's why i went with the avocado of those i have.