I tried to place a buy yes order for 0.14 and a buy no order for 0.84. The system told me that this is illegal because I'd be trading with myself even though those orders would not match and clear.
This restriction might just be a glitch that can be easily fixed. If it's intentional, I think you ought to consider removing this restriction.
When users intentionally try to place orders on both sides, they are usually doing it to capture the profit in between the ask and bid offers. This practice, called market making in other markets, is actually a very valuable service to the market. It reduces the price buyers have to pay and increases the price sellers can get. Moreover, it provides an extra source of market liquidity. Since liquidity is indeed a major problem for sparsely populated markets like this one, removing this restriction will go towards fixing that.
Market making is so valuable that stock exchanges usually pay market makers to do what they do. Allowing users to place orders on both sides will at least allow users to move towards correcting some of the more egregious bid/ask spreads.
If there are arguments against my proposal, please share.