Here is what I did to enhance blue lotus leaf. A small modification could allow you to harvest just the extract, leaving behind all the plant material.
I added acetone, water, and naphtha to 50 grams of blue lotus flowers and shook for a few minutes every hour, then let it sit overnight. The next day I shook it a few more times, then strained out the solvents. I evaporated the solvents down onto 5 grams of flowers and got 10x Blue Lotus. It works perfectly fine, and is easy to smoke. My friend will be using some of the 10x Blue Lotus, and if my Calea z. plant yields enough leaves, some 5x or 10x Calea to make Electric Sheep changa.
If you want just the extract, then evaporate the solvents down in an evaporating dish instead of evaporating them onto plant material. The reason I used three solvents is that I didn't know the solubility profiles of the various actives, so I just did a full-spectrum extract of all nonpolar, polar aprotic, and polar protic compounds that I could get out of the flowers.
If you don't want to use 3 solvents but you still want full-spectrum extraction, then using an alcohol together with a nonpolar solvent should work pretty well, as alcohols are polar but only weakly protic. You could mix, for example, naphtha and everclear to do the extraction, and you're likely to get most alkaloids out of the plant.