ICC for mac was recently updated maybe try it again.
Also its not true that ICC for mac is the only mac interface. If you go to chessclub.com and select the download link/button you are presented with icc for mac. but that page is tabbed and had mobile apps and web apps. On the Web App tab they show the web app at top but below are two Java interfaces anyone on Mac and Windows can use. you can use the older and popular Jin Chess ( mac will prompt you to install the legacy java if you don’t have it to run it) or Lantern Chess. Lantern will work on any version of java from java 6 ( the legacy mac java) to java 9 the soon to be released version of Java. Since they re applications not applets the fact that java may not work in your web browser wont effect things.
