Is bitcoin not in your portfolio, or is it only for altcoins that are in that bag? I think Bitcoin is important especially as a major asset that will soon be halving so keep a few percent there rather than nothing.
Altcoin HBAR is a very good prospect I saw some news that the project continues to do good development they also have good partners, I think it still makes sense for HBAR to be in your portfolio, then is ETH ruled out because it is too expensive?
I think ETH is good to include in the portfolio.
Maybe the OP is aiming for a project that can provide up to 10x profits and of course Bitcoin won't be on the list. ETH is also impossible to enter because even increasing 5x will be very difficult. So the OP's goal in owning altcoins is big profits. I don't have any other suggestions because the altcoins I invest in are the same as yours, but there are some that are not the same. I have CRO and TIA because I see both as very potential projects.
There isn't any hype about exchange project and only having a discount for trading fees or Earl access to new project token sale can not sustain a projects price if the team don't do market making. I don't think CRO can be a good investment for the long run but the 2nd token you are talking about is really amazing. But the problem is it's already overvalued and there needs to be a correction before you can take N entry to TIA I think.