Thanks for reminding me about OpenLedger! I have been looking at the decentralized exchange options out there, and the main qualification I look for is: Can I log in with my Ledger Nano S? Sadly most decentralized trade platforms don't offer this, and I think OpenLedger doesn't either. I will be trying the platform out though, it seems much nicer to use. Due to the lack of hardware wallet support I probably won't dare to do too much trading on there - I have gotten very paranoid with doing anything with my funds outside of my HW wallet; I really like the secure feeling it gives me. So adding Ledger nano S support would be my first and main suggestion, if possible.

As for the two options that you provided, I would choose the atomic swap option. As a potential user of the platform it is much more interesting to me to have as many trade pairs (preferrably 'real' BTC and not BitBTC - that really confuses things needlessly for newcomers). I believe there is the most to gain in drawing more people (volume) to the exchange, than it is to have as an ICO platform. SMTs are nice but beyond initial hype didn't do much for anyone yet. Also I believe the age of ICO's is coming to an end, there are too many platforms offering this option already. Focus on becoming the best DEX instead, increase marketing and take first mover advantage. Right now most people know Etherdelta, but don't know Bitshares/OpenLedger and that should change asap obviously!
Hope this feedback helps you in some way..

(p.s. Loopring, another crypto, is a protocol for DEXes which enables them to share eachother's liquidity - maybe worth looking into? It is currently Ethereum based though, but aims for cross-chain)