Don a good book with a summary of research on the sensation of knowing is Burton's "On Being Certain." There has been more research since then, but it's a good intro to the neurobiology.
We would be wise to always remember that our sense data is obtained subjectively, through the perspective of a particular subject, and although it is real it is never experienced as an absolute, objective point of view, there being no such thing. I think people who worry about including emotion and feeling do not understand that our brains function as a whole, and these aspects of experience are not really separable. But if we remember our senses are also subjective-- not opinions, but particular to subjects-- maybe that will place things in context.
Although I've just said we can't really fully separate our brain functions in everyday life, I'm going to break things down a little to show you what I mean by the difference between sense perception and abstract thought.
Seeing a table right now, in this moment, is a sense perception. Recognizing it as an object separate from the background is due to innate, rudimentary physics expectations-- a sort of pattern recognition present even in newborns, which I would term as a prolepsis rather than as a formal concept. The "object permanence" of the table, the expectation that it will still be there in the next minute, is a similar phenomenon which emerges on a tight developmental schedule, across cultures, which is not seen with purely learned cognitions. These innate physics expectations are strengthened by experience but are not solely empirical.
But too quickly for us to perceive, we immediately connect what we see with the word "table", the function of being able to put things on top of it, how it relates to similarly shaped objects, ideas about where the material came from such as the type of wood-- conceptual thinking. If I were to say "I know that is a table", I'm going beyond the Canon just a tiny hair, into concepts, but I'm still going to have a strong sensation of certainty. It would be hard to talk me out of it. If it started moving and growling, showing itself to be some strange animal camouflaged as a table, like in movies where characters step on what they think is a stone but which turns out to be a creature, I would change my mind, and this would also involve some conceptual thinking.
Even the words "I know I am really seeing what I'm seeing" are conceptual-- the whole idea that "there is a reality" is conceptual. But the experience of perceiving reality is non-conceptual. The idea of "truth" is conceptual, but encountering the phenomena we label as true is not conceptual. That actual perception is what we are talking about with the Canon.
Almost all our thinking involves some slight level of concepts of this type. However, in addition to concepts about knowing, we also have an inner sensation that goes with it, which isn't always accurate but is often more pleasurable to people than uncertainty. Moving from uncertainty to certainty is a dopamine, seeking driven process. We can want it without liking it, but usually that moment of discovery of a conclusion feels pleasurable and reinforces our wanting more.
Although the distinction between emotion and feeling is interesting, for most of us in real life we have strong associations between certain emotions and pain or pleasure. Epicurus was correct in assigning anxiety to the pain column. Some people do get an endorphin rush from fear-- that's why we have horror movies and roller coasters-- but the endorphin pleasure is a second event while the initial fear is not a pleasure. It's more of a pain that can lead to pleasure. For almost all of us, emotions like contentment, gratitude, or affection for others-- are pleasurable, and those words wouldn't be accurate communication with the feeling of pleasure removed. Try to imagine feeling gratitude that had no pleasure but pain instead -- it wouldn't make sense! Instead you'd choose a word like indebted or obligated or guilty. The emotion of guilt is painful-- if it were pleasurable we'd say satisfaction or pride in our actions.
Again, this sensation of knowing isn't always going to correlate with the level of certainty science can demonstrate-- a high degree of statistical probability regarding the causal chain. Even so, we can't extricate it from our experience of living, so it's useful, IMO, to know about it, to be conscious of it. Is it unsafe to enjoy it? I think Epicurus would object to that idea. He was very focused on relieving anxiety and substituting certainty. The wisest thing is to decide on some level of certainty such that you won't be highly upset if you are wrong, and it inevitably involves a subjective experience. You can't remove that from the process of a person deciding how much accuracy they want. If your level of accuracy is low, you'll possibly wind up with more pain than pleasure, so that's the main factor-- how much accuracy do you need for a pleasurable life? There can't possibly be an absolute answer to that question.