Unpopular opinion: I know his order doesn't see it like this, but I think what Ramakrishna proved was that the Shakta concept of ishta devata can extend beyond Indian religion. When Devi says she is the essence of all divine forms, she doesn't specify the likes of Jesus because he is not part of the Hindu tradition. From my point of view, it seems more like Ramakrishna was able to let go of the form and aspects of Kali and find new ways of connecting to Saguna and Nirguna Brahman.

The part I have an especially hard time with is, he would have had to let go of his understanding of non-dualism in order to practise monotheistic religions in their pure form, and I don't see how he would be able to do that after he had first hand experience of his reality of advaita.

However, what I do agree with is that other religions are true ways to experience divinity. I just think their own saints are better evidence of this than Ramakrishna is. Even though I do greatly admire him.

I learned how to do japa from reading Deepak Chopra lol. I'm not so much a fan anymore, but his book How to Know God was my favourite book when I was a teenager. I sometimes do other types of meditation as well, but japa is the only one I have done a lot of and consistently. It is only in the last few years that I started working with Patanjali's advice.

For what it's worth, I have read Ashtavakra Gita. I preferred Avadhuta Gita, but really they were both a bit much for me. I am still holding onto copies of them, in the hopes that if I come back to them in a few years, I might see something different in them.

The Upanishad I read most often is probably Mundaka. Shvetashvatara has some especially beautiful passages as well.