Thanks for the advice, I am only crunching Cosmology on a PC without VitrualBox so I haven't run into this problem but I will bookmark this article for future reference.
I have used app_config.xml to restrict memory hungry projects on my low spec computers but this is a much more detailed fix than I would have created on my own.
In windows, make sure you are using the UTF-8 enconding, and not the ANSI one
I have created ANSI encoded (default encoding for Notepad) app_config.xml files on Windows without any problems but it's also advice I will keep on file in case the encoding does ever cause issues for me.
Fellow BOINC hackers can find general information about the use of app_info.xml at https://boinc.berkeley.edu/wiki/Client_configuration
RE: A important warning to everyone trying to run cosmology@home in cpus with more than 8 threads.