I think other than using Hive Engine to exchange your LEO for HIVE, you can use Cryptex24 (https://www.cryptex24.io) to trade against BTC, USDT & C24 pairs. In case you missed the post about that, you can find that here:

@cryptex24/the-cooperation-post-or-leo-feat-cryptex24

Note: I have no experience using this exchange and please do your own research prior to signing up or using Cryptex24.