Add the ability for the reverse-proxy to connect via SSL to backends with self-signed certificates.
To do this would require an additional option in the VyOS config, which would in turn set ssl verify none in the HAProxy configuration.

Example of VyOS configuration:

set load-balancing reverse-proxy backend bk-default ssl no-verify

Example of how this would be rendered in HAProxy configuration:

server bk-01 127.0.0.1:9090 ssl verify none