Can the JSF support multiple faces configuration files?

Yes, any number of faces configuration files can be used but should be declared in the web.xml file as shown below.
 
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.1" xmlns="https://xmlns.jcp.org/xml/ns/javaee" 
	xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="https://xmlns.jcp.org/xml/ns/javaee 
	https://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">
<context-param>
	<param-name>javax.faces.CONFIG_FILES</param-name>
	<param-value>/WEB-INF/faces-config1.xml,/WEB-INF/faces-config2.xml</param-value>
</context-param>
</web-app>