It looks to me like political risk would be a lot more significant than vanilla currency risk over a 20-30 year period.

In what way, shape or form are they in any way distinct and separable for a country that is pegging its exchange rate? The exchange rate risk is a policy risk, combined with a risk of losing a capacity to enforce policy.

Substantial credit risks here are (1) the exchange rate risk and (2) the default risk of the actual borrower. From the perspective of US-based consortium raising funds in US$ capital markets, that default risk has to be seen as quite substantial. By contrast, for a Chinese-based consortium raising funds in China, converting what foreign exchange they require on a current rather than capital basis, the default risk seems likely to look much better compared to other investment opportunities in China.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.