I completely quit coffee and energy drinks (I'd still drink jasmine and peppermint tea) for a few months last year. No effect on HRT. I did experience an increased emotional depth which I suspect should have happened independent of what hormones I was taking (wow; this caffiene shit makes me agitated, who knew)
I propose an experiment which demonstrates computation on the (DMT-altered) human visual system. It is a simple visual stimulus/web application which when viewed while on DMT should solve a graph cut problem, using colour as input and hallucinated depth perception as output (see blog post for full explanation):
I hope. I haven't tested it yet. Prior art includes Scott Aaronson's experiment in using soap bubbles for computation[1], and Mark Chiangizi's efforts to build logic gates from Necker cubes[2]: