Not a direct answer to your question; but have you tried adjusting log levels off the runtime through the tray icon (or the runtimeconfig)? My solutions take a considerably longer time to load if the log levels are (too) high.
There are no command line arguments to enable logging. You would need to edit the RuntimeConfig.xml to enable/disable logging or change the log levels. I suppose a bat file could be written to copy a file first and then start runtime though.
Thanks for the tips on this - will try this see if I can get more diag out.
(I have a secondary problem now - when I load and run a project - I have asked a separate question: but the diag technique here might also work for that - not sure).