In ACF 8, the CFAjaxProxy tag didn't pick up inherited remote methods. This was fixed in ACF 9 and 10 and the official documentation now states:
I noticed that Railo supports an extends attribute to control whether inherited methods are picked up or not. Extends defaults to false. I realize this may have been done to match the default behavior of ACF 8, but it is now the opposite of the default behavior of ACF 9 and 10. I would like to suggest that the default value of the extends attribute for the CFAjaxProxy tag be changed to true to maintain compatibility with the version of ColdFusion that Railo 4 says it is compatible with (ACF 10).
Regardless of ACF's behavior, I also think it makes sense that inherited method would be picked up by default. All my web-accessible proxies inherit their actual methods from shared base components outside the web root for organization. When I extend a CFC, I expect the rules of inheritance to apply by default.