Ok, after doing tons of research SWIM sees no indication that a safe micro dose of Datura stramonium should cause any problems when used with bufotenine.

20 minutes ago SWIM took one 8 mg Datura stramonium seed (containing up to 56 micrograms of alkaloids of which most is hyoscyamine) and crushed it in his mouth thoroughly and swallowed it. This was followed 10 minutes later with a low dose of 30 mg freebase bufotenine taken sublingually and allowed to drain down into his stomach where it will cause nausea within 30 minutes guaranteed if the Datura stramonium doesn't work.

Right now, 20 minutes after taking the Datura stramonium seed and 10 minutes after taking the bufotenine, a very light pleasant stimulant effect is felt, mostly from the Datura stramonium. The effects of the bufotenine are just beginning.