RFE: Have /v1/agent/maintenance respond to GET with valid response codes

Ideally, there'd be a simple way to tell the state of a node via HTTP Response Codes. Even better would be via a HEAD vs. GET request, so that things like Load balancers can auto remove nodes based upon failures. Specifically
/v1/agent/maintenance GET/HEAD - 503 when in maintenance mode
/v1/agent/maintenance GET/HEAD - 200 when not in maintenance mode

Another end point that should return a 503 response code as well:
/v1/agent/checks

It'd be nice if /v1/agent/checks also responded to a HEAD request with the response code for simple health checking/monitoring