Slippage is absolutely brutal with Bitmex market stop losses- limit stops almost never work, and even market stops in profit after fees often end up in a loss if price is swinging fast in one direction or the other, unfortunately. Any leveraged trading sites similar to Bitmex including Bybit will likely require KYC for American traders in the future as well, and if you really want to trade on these sites, a VPN's the best way to go. Your ping's generally not increased by a whole lot with VPNs, and a simple Canadian VPN (no Quebec IPs, though) should be enough.
I spotted there was a release of a decentralised leverage trading exchange on this forum but I didn't get chance to take a look at it, it seems that decentralising or adding more servers is the way to go for bitmex so maybe once they've evolved a bit the decentralised exchanges will be better but no one seems to make a DEX mobile app.
Interesting, if you find the link to the exchange you're talking about, it'd be great if you could drop it here but there might be problems with liquidity for the exchange you're talking about initially after launch which could cause problems with trading. Not a big fan of decentralized exchanges as of right now, and most of them don't seem to be very popular but I'm always looking for something new.