The most important thing is that Neurologically they produce very similar effects with fMRI studies.
Deactivation of the vmPFC(thinking thoughts/analysis) and deactivation of the Default Mode Network (Ego) only with psychedelics you get a lot more artificial activity going on in the occipital & paraitel lobe (visual processing areas)
So would low doses of dmt/psilocybin help the mind with the progression of meditation? I would say so because neurons work via sink or swim... that is neurons that fire more frequently will continue to fire more frequently... Hence why some people get afterglow from trips or even HPPD.
Personally, I find threshold visual doses to help get me comfortable and centred enough to not make beginning meditation difficult. A lot of people just sit there and are really bothered by both there thinking and how there awareness is which is responsible because of both of those areas discussed (vmpfc and the dmn) So a little help with these puppies is a great tool for getting over those first few hurdles, but once you are doing it frequently for long periods I think they would become redundant as the brain would have switched over to a different type of processing.
In answer to your question though, they are both different teachers and offer different experiences even though what is described of them by people may be similar in language, it is a different case subjectively (the difference between ego-loss on mushrooms must be subjectively quite different from ego-loss from zen)
Psychedelics take a lot of courage & dauntlessness of the undefinable & unkown, Meditation takes a lot of persistance & discipline in becoming the undefineable & unkown. One may be more rewarding, one may be more exciting or enjoyable depending on the person.
Psychedelics and the “Default Mode Network”The default-mode, ego-functions