Cherokee rule failover

Question

I have a Cherokee virtual host configured as follows:

1st rule: "Directory /" -> HTTP Reverse Proxy
2nd rule: "Directory /" -> uWSGI

I know the second rule is useless because it's never triggered.

However, the first rule seldom returns a 504 Gateway Timeout error so I was thinking of failing over the second rule, yet I don't know how to achieve this.

Is it possible?

Unfortunately, I cannot use only one rule with load balanced information sources, because I use two different types of information sources (i.e., pure HTTP and WSGI).