I think there isn't much advantage in spending for listing on LEO DEX. LEO community is a small community and that is actually a small subset of total SE tribe membership. So everyone is already using the SE platform. User Interface won't make much of a difference as anyone interested can go to the SPI market page through clicking on the link given in your posts.

Even if listing is cheap, it doesn't mean we should go for it. It's better to provide liquidity on a single platform for now. Once transaction volume increases, we can think of listing at other places too but I don't find it any compelling as of now.