Apple have released new GM seed versions of Xcode 10.3 and 11.1 as far as I know, we’re going to start working on building the images as soon as we can.
I’m going to make Ruby 2.6 be the default ruby on the images to work around the header issues that we see building native Ruby extensions in Xcode 11.
There didn’t seem to be any release of a 10.3.1, so I think we are all up to date with the latest Xcode versions now, and the 11.1 image has the Xcode 11 CLI tools installed, too.
I’m working on changing the default Ruby to 2.6 no for Xcode 11 and newer, and once that’s fixed I will look at adding more simulators.