Thanks for asking this here @ch_kent!
15.2.2 will be rolled out this weekend
Sure, we’ll prepare & test it on Friday and deploy the updated VMs on Saturday as usual (How are the bitrise.io stacks updated and with what frequency? What's the stack deprecation / removal policy?)
AFAIK it should solve the issue as Xamarin Studio uses the same core components as Visual Studio for Mac, and we install Xamarin Studio as-it-is, without any customization other than turning off automatic updates and setting the log level to Quiet (https://github.com/bitrise-io/osx-box-bootstrap#xamarin-notes)