I'm not sure with what you called as unknown token. Is that the newly token created or coin listed in certain exchange which is not top coins? Or, ar eyou looking for token with more than #1000 rank on CMC? Or are you looking for new token where there is only few people who want to invest in it?

This is exactly risky. I know that many members here support what you want. But, honestly, I will prefer  to say, please be careful on your investment.
This seems to be high risk,  too. Because after all, we may analyze a new project with our own analysis. but does that guarantee that our analysis is correct, whereas not many people also analyze these tokens because they are unknown tokens? Then, are you sure that these unknown tokens will really be successful in listing on exchanges, especially on top exchanges, even though are they unknown tokens?

In my opinion, this is no different from choosing a hype token, which is also full of risks. The difference is that token/coins hype might be more promising as long as we understand when to get in and when to get out, by taking advantage of the hype moment. And not for long-term investment. However, for this unknown token, I might even think it is a token that is not well known and perhaps has not been listed on the top exchange. So, who knows whether this token will be able to survive in the market or not. the risks are also equally great.

Personally, I'm not the type of high risk taker. So I would prefer to choose popular tokens or coins that are at least in the top 10. I don't want to be idealistic by avoiding top popular exchanges. Why? Because so far, I have made quite a decent profit from these coins.

But that's up to you, at least you will first know your unknown tokens to be picked.