Ancient Greek famously made a distinction between 3 kinds of knowledge: doxa, episteme, and gnosis.
Doxa is basically what in English we might call hearsay. It's the stuff you know because someone told you about it. If you know the Earth is round because you read it in a book, that's doxa.
Episteme is what we most often mean by "knowledge" in English. It's the stuff you know because you thought about it and reasoned it out. If you know the Earth is round because you measured shadows at different locations and did the math that proves the only logical conclusion of the results is that the Earth is round, that's episteme.
Gnosis has no good equivalent in English, but the closest we come is when people talk about personal experience because gnosis is the stuff you know because you experienced it. If you know the Earth is round because you traveled all the way around it or observed it from space, that's gnosis.
Often we elide these distinctions. Doxa of episteme is often thought of as episteme because if you read enough about how others gained episteme you may feel as though you have episteme yourself. We discover this is not true, though, when we actually develop episteme of something we previously only had doxa of episteme of, like when we try to teach another person something and discover we didn't understand it as well as we thought we did. Similarly, episteme is sometimes mistaken for gnosis because episteme may allow you to always get the expected answer the way gnosis usually lets you, but only so long as you put in the effort to reckon epistemologically.
Many rationalist thinkers focus heavily on episteme and the doxastic logic used to combine facts. This is fine as far as it goes: you need to be able to develop well-formed episteme from facts if you want to have much chance of winning. Humans are notoriously bad at episteme and it takes considerable training to become good at it, and episteme requires constant maintenance to remain accurate. We cannot hope to be rationalists if we cannot master episteme.
But there is something more if you want to walk the Way. It's not enough to know about the Way and how to walk it; you need gnosis of walking. And I know this (doxastically, epistemically, and gnostically) from listening to others describe their experiences, reasoning about epistemology, and remembering my own experience learning to walk the Way.
This would be a purely academic distinction if it weren't for the fact that I see many of my rationalist friends suffering and finding consistently that those who suffer the most tend to be those with the least gnosis of rationality. And this is further complicated because those with gnosis do not always have the most episteme, so those more skilled at epistemic rationality may reasonably ignore the doxa of gnostic rationalists as confused at best and self-deceptive at worst. And so I find myself between a rock and a hard place because I see my friends suffering and I know (epistemically) how they can be helped but I don't know (gnostically) how to help them.
All I know how to do is leave breadcrumbs for those without so much dust in their eyes that they can see the breadcrumbs well enough to keep following the Way when they find they are no longer walking it. This, however others may perceive it, has been the motivating goal, at least for me, with what we've lately been calling "metarationality". That is, to figure out how to help our epistemically rationalist friends learn to be gnostically rationalist. My writing and the writing of David Chapman, Kevin Simler, Sarah Perry, and others is a way to gain doxa and maybe even episteme of our gnosis, but other than maybe Chapman's proposed curriculum, we have not really found a reliable way to guide people towards gnostic rationality.
But maybe "gnostic rationality" is a better name than "metarationality", and one more people can get behind. After all, I already see primarily epistemic rationalists engaging in practices to develop gnosis through things like comfort zone expansion (CoZE) and using the double crux in their own lives when the stakes feel high, and gnostic rationality, by the very nature of being rationality, does not work without episteme enough to judge what may help you win and what may not. Thus it is not that anyone is seeking to go beyond rationality so much as fully engage with it, not just with our words (doxa) and minds (episteme), but also with our hearts (gnosis). This is the Way of gnostic rationality.