Hyoscyamine could be added aswell, itīs more stimulating.
While scopolamine is more sedating.
Daturaīs alkaloids ARE known to strongly potentiate serotonergic psychedelics at those doses. Hence the why shamanīs sometimes add it to ayahuasca (another obvious reason is that it combats nausea)
itīs quite plausible that it has been done, while certainly not being common.