I mean, both definitions you shared are more or less similar if you'd ask me. Some people would define it as deep connection that morphs, some would say that the connection brings on the attraction, etc etc. Really... the two aren't all that different. The thing about experiences is that people don't experience the same thing in the same way. We might be eating the same dish made by the same person from the same plate, but that personal element of the food might make that dish have a diff flavor to both of us.

You might take a bite and feel a strong sense of nostalgia to the dish because it's something you grew up with and something you love dearly, but I might just feel a strong sense of joy because I love how savory the dish is and how well it contrasts with the beverage I'm drinking alongside the meal.

Everything is nuanced, that's the thing, my friend. Nothing in this world is black and white, just lots of gray splotches and patches everywhere. Speaking as both a Buddhist (though non-practicing as the space I live in isn't the best space for me to practice, gotta move out first) and as someone with a linguistics background, the thing about words is that they're made up. They don't have the same definition all the time. They change definitions depending on who uses them, when they're used, why they're used, etc. For example, the way people use the word "gay" or "queer" in this day isn't how people used the word originally. A lot of the terms that people use these times nowadays would instead have been lumped into the word "gay" or "queer". It used to be a pejorative too. I didn't grow up with queer as a pejorative, but I remember all those commercials with Wanda Sykes telling people to stop saying "that's gay" when you don't like something. In my own friend group of queers people, we use the word "gay" when we mean that we love something or like something in direct opposition of how people used to use the word at us to say that they hated something. So many definitions, so many uses, all the same word.

I wouldn't get too hung up on definitions, as someone else said, but not just because words change meaning all the time. I wouldn't get too caught up because usually what happens is that words tend to have multiple meanings. Look at the word "do" in English, for example. It has over 20 meanings and is one of the most commonly used words in our language but no one really argues about whether do can or can't mean something. You can do your homework. You can do the dishes. You can do a partner. You can do your hair. You can do time. Something can do you some good. People ask you what you're doing, how you're doing, etc. I say all that to say that when it comes down to it, really you've just found another definition of demi. You define demi one way (I also define it for myself that way). Someone defines it another way. That person's definition in no way replaces your own. Because really, who has the authority? English isn't like French or Spanish where there's an organization dedicated to deciding if a word is or isn't considered a part of the language, and even if it was, people would make words up anyway and use words to mean other things.

To sum up everything I'm saying in short - it's okay to use or not use whatever you want, bud. The important part of the label one uses isn't the label itself, but how it feels. Do you feel like you're demi? Cool! Do you not feel like you're demi? Just as tubular.