The file useragentswitcher.xml is not quite up to date either. For instance, Firefox is up to v. 58, but it only goes ot 57. Chrome is up to v. 64 (at least) and it goes only to Chrome 62. Opera is now at v. 51, but the list takes it only to 47.
Jul 14, 2013 - See following posting for basic changelog. You can use either method to download the current UserAgent Switcher List 2.x.x xml file: Download.
That is for Windows. The list for MacOS is even worse. Chrome is only up to v.
61, Firefox only up to 55, Opera only up to v. 29, SeaMonkey only up to 2.7.1. I am using User Agent Switcher in Pale Moon. I added the Pale Moon information block to install.rdf in the.xpi file, since I do that as a matter of course anyway.