Good luck with your experiment Cosmic, the deliriants are a fascinating class, used to love reading whacked out trip reports on Erowid a while back, not sure I will ever take the plunge myself though. Can these plants really be called "entheogens"?

Never really heard that term applied to them before, maybe lower doses are different though as you are intending, if I understand you. Atropine and scopolamine seem to be particularly dangerous physiologically even besides the fairly precarious psychiatric effects which is another thing that puts me off... Atropine especially... not sure if there are other milder tropane alkaloids though, been a while since I read about this particularly scary class... but again maybe low doses can mitigate a lot of these dangers.
Edit: Oh I see you mentioned Hyoscamine above
@Cream Gravy?, is that a naturally occuring tropane? Do you know how it compares to the other 2 I mentioned above, either physiologically or psychologically?