Why combine Psychedelics with EEG Biofeedback?

First of all, why not, given that people have spiritual experiences with psychedelics as well as alpha feedback.

But what probably gave me the idea was an excerpt from a paper on ayahuasca that included a brief survey of research on psychedelics and brain waves:

The majority of EEG studies done on psychedelics appeared in the scientific journals some 30 years ago before these compounds were banned. Wikler (1954), Itil (1968) and Fink (1978) are all in agreement that psychedelics, regardless of the substance (LSD, mescaline, psilocybin), produce decreases in slow wave (alpha and theta) activity together with increases of fast (beta) activity. This low amplitude, desynchronized EEG pattern induced by psychedelics reflect an activation of the brain and is in opposition to the highly synchronized alpha pattern observed during deep relaxation. Fink (1978) found that regardless of the nature of the drug administered, EEG synchronization (alpha/theta waves) was associated with euphoria, relaxation, and drowsiness; while EEG desynchronization was associated with anxiety, hallucinations, fantasies, and illusions.

I for one, vote for euphoria and relaxation over anxiety and illusions.