The HAProxy Stats is a great and powerful instrument. It provides gives you the followning opporunities:
On the HAProxy Stats page you also can manage frontends and backends.
This option allows to temporarily disable backend servers and switch them to the maintenance mode:
Select the servers and in select the action to perform in the Select menu as it is shown on the picture:
Press the "Apply" button and reload the page:
W Also Roxy-WI allows to filter frontends and backends by the status. If you do not want the backenes with servers in the maintenance status to be displayed, just remove a check box as it is shown on the picture below, and they will be excluded from the output>