Just a quick question, has anyone ever used the stem and leaves only? For extraction of harmalas and\or smoking on its own? My plants never give seeds so i wonder if i should use the aerial parts instead, since they die off each winter anyway. Thanks

Here is a study showing the percentage on stems and leaves - c. 1.5% (page 562)

study

Not I.
But I did once harvest leaves for smoking. The odor of sulfur compounds in the leaves put me off, the seeds dont smell like that even when fresh and I didnt want to gamble on it being safe.
I'd suggest purifying the alkaloids out before using it.

I've never smoked leaves or stems, but I decided to try smoking the roots after one of my plants died. It was definitely effective. It tasted like smoking wood, but aside from that it was a pleasant experience. I ended up grinding some up and mixing it in a joint with some reefer. Noticed some CEVs afterwards.