If I would search for hidden gems, I would differentiate two possible strategies:
1) Short-term. This is basically a gamble. Research thoroughly, try to identify short-term trends (BRC-20 may have been one in mid-2023, but now I think the bubble is close to pop). I've heard a current short time trend may be Layer 2 coins for Bitcoin, but again, research them, because there are lots of dubious projects (one starting with the name of Bitcoin's founder, for example). Of course: If someone in this forum recommends you a specific coin, stay away because it's very likely that they're a bagholder
2) Long-term. You can try the "revive dead coins" strategy. There are about 20000 altcoins. If you look at the lower part (position 1000 on Coingecko/CMC downwards), some look like they're almost dead and you can buy high quantities for a low price. If you are able to inject new life in the community the returns may be huge. I would only choose coins with a fair launch and good distribution, because this means there may be some loyal people around in the surviving parts of the coin's community who will help you defend the coin. If the distribution was centralized/uneven and the founders left the ship, all old community members are likely to be angry and feel scammed, and lots of coins by bagholders (and remaining project founders) may be dumped fastly.
BRC20 tokens
Only a personal opinion, but BRC-20 is the most useless, most anachronistic (you need TWO transactions to move the tokens!) and most despicable technology I ever have seen* on the Bitcoin chain. It is even likely that they're used by some entities as a deliberate attack on Bitcoin's usability (because they lead to spam on the blockchain).
I would strongly recommend against BRC-20. See
here for reasons.
They may see another bull run, but they have already seen a lot of price appreciation based on absolutely nothing in late 2023. They're far from being "hidden" gems.
(* - with the exception of those who have stored links to violence against children and other crap on the blockchain, but that can be hardly called a "technology").