In a multiple server environment, I have deployed both Caddy and FRPS services on two separate servers. The domain 'a.xx.xx' is resolved to both servers, and users are directed to the nearest server based on DNS resolution. I want to achieve a setup where the FRPC client connects to both FRPS services simultaneously. Alternatively, I can use a single domain to resolve to both FRPS servers and configure the client to connect to the nearest server. Additionally, I have Caddy configured for load balancing and checking the backend service's availability, but it always returns the default 404 error from the FRPS service, regardless of its status. This results in Caddy redistributing traffic between the normal and abnormal FRPS services. I need a solution to make the FRPC client return an error for the unregistered FRPS service instead of attempting a connection.