I found the following article an accessible gateway to a more nuanced contemplation of some of the ways in which different aspects of reality integrate.
https://zenstudiespodcast.com/sandokai-1/
Reality is undeniably multidimensional, whichever metaphysic one favours. My own view allows that the relative dimension of reality, as the article calls it, may itself be multidimensional, comprising at least one dimension amenable to perception, and at least one further dimension transcending perception though tangentially amenable to other modes of cognition; I consider the absolute dimension of reality, on the other hand, to be unconditionally one – and approachable only through contemplative oractices – which I feel lends it a qualified primacy congruent with the primacy afforded the RH by Dr. McGilchrist.
The left and right hemispheres, in my own experience and as evidenced in the words of more seasoned meditators, appear equally necessary, though perhaps not equally ancillary, to meditation. Mindfulness-based meditation, for instance, as the following video suggests, appears to require, at the very least, a combination of focussed attention (LH) and sustained attention (RH), to use Dr. McGilchrist’s terms.
https://bigthink.com/neuropsych/benefits-science-meditation-mindfulness/
Finally, the link below suggests that meditation may entail a spectrum of hemispheric involvement, from predominantly LH (“close focus to our breath or a sensation” – sustained, focussed attention), through an equilibrium of LH and RH (“a breath, a pain in our legs, a thought about dinner, a feeling of sadness” – sustained, focussed and divided attention), to predominantly RH (“experience the mind’s awareness as open, boundless and vast” – broad, vigilant attention, as Dr. McGilchrist calls it, or if you prefer, pure sustained attention).
https://www.lionsroar.com/a-mind-like-sky/
Despite demurring otherwise, the author tacitly elevates predominantly RH involvement. (After all, the article’s title and the obligatory Buddha quote both allude to it.) This left-to-right progression (and implicit promotion) is also evident in a method for developing increasingly effectual meditation expounded by B. Alan Wallace in his excellent book, The Attention Revolution. (Yes, that was a plug.)